I think everyone is afraid of your question because it is a little complicated and not completely clear. But I will try to help you if you are willing to do a little work to help yourself; it seems like you are not afraid to learn, which may be part of your problem - you may be taking too big a bite (byte?). :)
My first recommendation is to forget about so many different partitions for now. It will just make it more complicated, and is probably not necessary, but if you decide later that it is, you can change it fairly easily.
About GRUB, as I understand it... There are two things to think about. The first is where the actual boot loader lives, and the other is where the rest of GRUB (and usually the OS files) lives. When you boot, the drive is not very smart, and all it wants is to be told where to go to find help in booting. So there is some small amount of code in what's called the MBR (master boot record) to accomplish this. There is a newer scheme used only by recent Windows systems, that use something called GPT, but I have no experience with this. Hopefully, you don't have newer versions of Windows on the drive. If so, be sure you have a Windows boot disk for recovery.
Anyway, the normal way to install GRUB is to install it to the MBR (sdb, not sdb1). Then, the rest of GRUB is installed in the OS partition (sdb1, in your case), and the MBR part is told to look there. If you install another version in a different partition, it will tell the MBR part to look in the new partition, and usually will copy the old settings to the new partition. But if you delete the new partition, it will no longer work until you tell the MBR part to go back to the old partition.
I have no idea how to deal with installing it to a partition like sdb1; I suspect that it will only work if you have something in the MBR that can chain load that partition, the way GRUB chains to Windows.
Let me know if you need more specific help. Also, there are bootable utility CDs you can make that can fix these problems automatically, but it's a good idea to understand basically what's happening first.
Hope this helps, but if not, let me know.