Large Betta Aquarium ! ? !?

I have been taking care of betta fish for about 4 years now. Since then I have had about 4 betta fish, but saddly died. I currently bought a little One Gallon tank for two of new betta fish (Grumpy and Bashful). The tank is divided. I have been looking at alot of places online and plan on going looking at a few pet stores tomorrow to see what I find. But all together I am planning on having 7 or 8 bettas in a tank, that is divided. I would like for them to have a space of 4-5 inches length and idc wide. I might go longer, all depends on what I find. I would like to have a 36inch length tank. Im not brand picky. I am just looking for some ideas and comments and thoughts on where to get my tank. I can already see how it is gonna look in my head but it seems to be harder to find what I want out of my head. (Before anyone can say anything, Yes I am naming them after the 7 dwarfs). So if you have any idea on where I should get my tank please help, or feel free to give suggestions.