For your 64 bit system, I'd first try the Kokua viewer from kokuaviewer Downloads. That should install and run on your system without problems (assuming you have the sound already working). The voice chat feature works, but its implementation does not have Linden Labs' blessing, so may go away in the future. In that case, you will have to switch to the approved mechanism and run the secondlife Windows voice program under wine (like you would have to do for the official viewer).
If you really want to get the necessary 32 bit libraries, here is a list from the second life bin file:
$ ldd do-not-directly-run-secondlife-bin
linux-gate.so.1 => (0xf773d000)
libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xf76ef000)
libfreetype.so.6 => /usr/lib/i386-linux-gnu/libfreetype.so.6 (0xf763f000)
librt.so.1 => /lib/i386-linux-gnu/librt.so.1 (0xf7635000)
libhunspell-1.3.so.0 => not found
libopenal.so.1 => /usr/lib/i386-linux-gnu/libopenal.so.1 (0xf75be000)
libalut.so.0 => not found
libgobject-2.0.so.0 => /usr/lib/i386-linux-gnu/libgobject-2.0.so.0 (0xf755f000)
libglib-2.0.so.0 => /lib/i386-linux-gnu/libglib-2.0.so.0 (0xf7435000)
libGLU.so.1 => /usr/lib/i386-linux-gnu/libGLU.so.1 (0xf73bb000)
libGL.so.1 => /usr/lib32/nvidia-375/libGL.so.1 (0xf7338000)
libX11.so.6 => /usr/lib/i386-linux-gnu/libX11.so.6 (0xf71ed000)
libfmodex.so => not found
libGLOD.so => not found
libSDL-1.2.so.0 => not found
libgdk-x11-2.0.so.0 => /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0 (0xf712c000)
libgthread-2.0.so.0 => /usr/lib/i386-linux-gnu/libgthread-2.0.so.0 (0xf7129000)
libgtk-x11-2.0.so.0 => /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0 (0xf6c33000)
libexpat.so.1 => /lib/i386-linux-gnu/libexpat.so.1 (0xf6c08000)
libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xf6c03000)
libfontconfig.so.1 => /usr/lib/i386-linux-gnu/libfontconfig.so.1 (0xf6bba000)
libaprutil-1.so.0 => not found
libapr-1.so.0 => not found
libstdc++.so.6 => /usr/lib/i386-linux-gnu/libstdc++.so.6 (0xf6a42000)
libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0xf69ed000)
libgcc_s.so.1 => /lib/i386-linux-gnu/libgcc_s.so.1 (0xf69d0000)
libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xf681a000)
/lib/ld-linux.so.2 (0x565c8000)
libz.so.1 => /lib/i386-linux-gnu/libz.so.1 (0xf67ff000)
libpng12.so.0 => /lib/i386-linux-gnu/libpng12.so.0 (0xf67d3000)
libffi.so.6 => /usr/lib/i386-linux-gnu/libffi.so.6 (0xf67ca000)
libpcre.so.3 => /lib/i386-linux-gnu/libpcre.so.3 (0xf6755000)
libGLX.so.0 => /usr/lib32/nvidia-375/libGLX.so.0 (0xf6735000)
libGLdispatch.so.0 => /usr/lib32/nvidia-375/libGLdispatch.so.0 (0xf66b5000)
libxcb.so.1 => /usr/lib/i386-linux-gnu/libxcb.so.1 (0xf668e000)
libpangocairo-1.0.so.0 => /usr/lib/i386-linux-gnu/libpangocairo-1.0.so.0 (0xf6680000)
libpango-1.0.so.0 => /usr/lib/i386-linux-gnu/libpango-1.0.so.0 (0xf662f000)
libgdk_pixbuf-2.0.so.0 => /usr/lib/i386-linux-gnu/libgdk_pixbuf-2.0.so.0 (0xf6606000)
libgio-2.0.so.0 => /usr/lib/i386-linux-gnu/libgio-2.0.so.0 (0xf643d000)
libXrender.so.1 => /usr/lib/i386-linux-gnu/libXrender.so.1 (0xf6430000)
libXinerama.so.1 => /usr/lib/i386-linux-gnu/libXinerama.so.1 (0xf642c000)
libXi.so.6 => /usr/lib/i386-linux-gnu/libXi.so.6 (0xf6419000)
libXrandr.so.2 => /usr/lib/i386-linux-gnu/libXrandr.so.2 (0xf640c000)
libXcursor.so.1 => /usr/lib/i386-linux-gnu/libXcursor.so.1 (0xf6401000)
libXcomposite.so.1 => /usr/lib/i386-linux-gnu/libXcomposite.so.1 (0xf63fc000)
libXdamage.so.1 => /usr/lib/i386-linux-gnu/libXdamage.so.1 (0xf63f8000)
libXfixes.so.3 => /usr/lib/i386-linux-gnu/libXfixes.so.3 (0xf63f1000)
libcairo.so.2 => /usr/lib/i386-linux-gnu/libcairo.so.2 (0xf62b0000)
libXext.so.6 => /usr/lib/i386-linux-gnu/libXext.so.6 (0xf629b000)
libgmodule-2.0.so.0 => /usr/lib/i386-linux-gnu/libgmodule-2.0.so.0 (0xf6295000)
libatk-1.0.so.0 => /usr/lib/i386-linux-gnu/libatk-1.0.so.0 (0xf626e000)
libpangoft2-1.0.so.0 => /usr/lib/i386-linux-gnu/libpangoft2-1.0.so.0 (0xf6256000)
libXau.so.6 => /usr/lib/i386-linux-gnu/libXau.so.6 (0xf6252000)
libXdmcp.so.6 => /usr/lib/i386-linux-gnu/libXdmcp.so.6 (0xf624a000)
libthai.so.0 => /usr/lib/i386-linux-gnu/libthai.so.0 (0xf623f000)
libselinux.so.1 => /lib/i386-linux-gnu/libselinux.so.1 (0xf6219000)
libresolv.so.2 => /lib/i386-linux-gnu/libresolv.so.2 (0xf6200000)
libpixman-1.so.0 => /usr/lib/i386-linux-gnu/libpixman-1.so.0 (0xf614f000)
libxcb-shm.so.0 => /usr/lib/i386-linux-gnu/libxcb-shm.so.0 (0xf614b000)
libxcb-render.so.0 => /usr/lib/i386-linux-gnu/libxcb-render.so.0 (0xf6140000)
libharfbuzz.so.0 => /usr/lib/i386-linux-gnu/libharfbuzz.so.0 (0xf60dc000)
libdatrie.so.1 => /usr/lib/i386-linux-gnu/libdatrie.so.1 (0xf60d2000)
libgraphite2.so.3 => /usr/lib/i386-linux-gnu/libgraphite2.so.3 (0xf60aa000)
and the voice program:
$ ldd SLVoice
linux-gate.so.1 => (0xf772f000)
libortp.so => /usr/local/vm/work/Second_Life_5_0_3_324435_i686/bin/./../lib/libortp.so (0xf76fb000)
libsndfile.so.1 => /usr/local/vm/work/Second_Life_5_0_3_324435_i686/bin/./../lib/libsndfile.so.1 (0xf76a1000)
libvivoxsdk.so => /usr/local/vm/work/Second_Life_5_0_3_324435_i686/bin/./../lib/libvivoxsdk.so (0xf7055000)
libvivoxplatform.so => /usr/local/vm/work/Second_Life_5_0_3_324435_i686/bin/./../lib/libvivoxplatform.so (0xf6f57000)
libvivoxoal.so.1 => /usr/local/vm/work/Second_Life_5_0_3_324435_i686/bin/./../lib/libvivoxoal.so.1 (0xf6f0f000)
libz.so.1 => /lib/i386-linux-gnu/libz.so.1 (0xf6ec8000)
librt.so.1 => /lib/i386-linux-gnu/librt.so.1 (0xf6ebe000)
libresolv.so.2 => /lib/i386-linux-gnu/libresolv.so.2 (0xf6ea5000)
libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xf6ea0000)
libidn.so.11 => /usr/lib/i386-linux-gnu/libidn.so.11 (0xf6e6c000)
libuuid.so.1 => /lib/i386-linux-gnu/libuuid.so.1 (0xf6e66000)
libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xf6e48000)
libstdc++.so.6 => /usr/lib/i386-linux-gnu/libstdc++.so.6 (0xf6cd1000)
libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0xf6c7c000)
libgcc_s.so.1 => /lib/i386-linux-gnu/libgcc_s.so.1 (0xf6c5f000)
libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xf6aa9000)
/lib/ld-linux.so.2 (0x5659d000)
Note that some libraries are missing in my setup, but they don't affect what I do. Also, the (Linux) voice library setup is pretty useless since the libvivoxoal never got set up completely (like the Kokua setup did), so the Linux voice program can never run. The approved voice setup is to install Windows SL under wine, and run that SLVoice under wine. That does work successfully with the 32bit SL Linux SL viewer.