Well I have some new found insight after doing a little reading and checking out that link you provided. All in all you should be fine as long as you're patient and very meticulous during construction. The weight of the water shouldn't be a problem as long as the glass isn't in a bind when filling with water. Any configuration you choose should work as long as you don't try to increase the height of the tank using only the glass you have from the provided aquariums. I would look at the DIY all galss build in the link I provided to get the silicone he uses. Eurobracing would totally work too if done properly. Also if you did the seams properly you could get away with using glass as the bracing on the sides instead of wood.