~50gal fermenter?

[fiery creations]

Anyone have a recommendation on a good fermenter around 50-100 gal size? Read through some some posts and it sounds like I'm asking for trouble using aquarium heaters inside my home so I'd like to find a better, slightly professional setup with heating a little bigger and nicer than my current hillbilly setup. The local beer shops quoted several thousand which I'm not looking to spend. Is there a DIY setup in this size range that someone can point me towards that isn't a several thousand dollar stainless conical beer fermenter?