i was in a minnesota bar once and saw a native tank setup. they had walleye, bass and the like. they were in what appeared to be a 150 gal, or so. you just have to make sure they are all around the same size.
Walleye are open water/big water predators - never a good start for aquarium keeping. Not to mention the fact that I've seen people catch 20+ pound fish...
Sounds really cool. I raised large mouth bass and they are a lot of fun also. I am now looking at raising some northern pike. I never tried them yet. The future is looking great for me. Good luck.
walleye are a very fragile fish they will catch stuff very easy if they are stressed. I would strongly advise a chiller for any fish over 12" although they can live at warmer temps they will be stressed and may catch something.