There is Matamoros JJ, Duke Roufus Muay Thai, Neutral Ground JJ, Fighting Irish MMA, and a slew of others I can't think of right now in Milwaukee. In Madison there is twisted Fitness, there are others but Twisted is where it's at.
Really depends on what you are looking for, all of the schools have accomplished fighters. Post on the WI BJJ growing strong thread for more info.
Edited to add: Madison and Milwaukee are like an hour apart so their not really in the same area so you might want to consider that as well.
There are well trained fighters there, Nick Agallar, Brian "Duke" Geraghty, Jameel Massouh, Rob Roy, Ray Ray Hunter, and of course, Dave Strasser. I don't know your weight, but these guys are 155-185's. If you're heavier, there are some guys there to beat on, me.
Friday is preferrable, we start around 6 pm. Saturdays are a little sketchy it really depends on last minute arrangements, we usually dont decide anything for the weekend until a few hours before. If you shoot me an email rdub7414@yahoo.com with contact info I could let you know, I will also to need to get The Don's (Matamoros) blessing for bringing in a nonmember for weekend training, but your golden for Friday. I will let him know about he UG Grand Prix thing, he may find it interesting and be all for you coming in.