I didn't glue any of the pipe joints, though I did put screws through the toilet flange into the tube (I wanted to be able to take it apart).
You can't get regular shanks for a tower, you need to get elbow shanks. Kegworks.com sells a nice kit
that comes with the shanks, hose and faucets (they call it a refurbishing kit). I bought two of those kits and they worked amazingly well, you just cut off the threaded fitting they supply (they're for commercial kegs) and either add the flare fitting for a QD (or just the QD itself).
You'll also want more than 12" of pipe, most places only sell it in 3' lengths anyway but to give you an idea, my tower is 14" from the top of the kegerator to the top of the tower. That gives me a good 10" below the faucet.