So I visited the Lubuntu download page (specifically because it's lightweight), which happens to be hosted in the Ubuntu Help section of it's website. I tried to find a version of Lubuntu similar to Ubuntu Server (no GUI, visible stacks), but I couldn't find any. Any feedback is appreciated.
The only difference between Ubuntu and Lubuntu is that they both use different Desktop Environments and some different packages. Ubuntu uses Unity whereas Lubuntu uses LXDE.
According to Lubuntu Wiki:
So, essentially Ubuntu Server with no GUI would be the same as Lubuntu Server with no GUI. Hence, you can go on downloading Ubuntu Server and install LXDE later, if you want a Lubuntu like GUI.