WI is almost a zero-gun-control state.
We have only 2 gun control laws:
1) There is a 3-day waiting period on pistol purchases while a state background check is conducted (in addition to NICS)
2) No concealed carry, except inside of your home or business premises (The 'exception' exists due to the WI Supreme Court finding a total prohibition unconstitutional - we have an explicit individual RKBA in the state const. Prior to this, it was no CCW period. It was technically illegal to put your guns in a safe).
Everything else is legal, so long as you comply with Federal law... Age limits and everything else are basically 'same as Federal'. No special IDs, or other tack-ons... The only other gun law makes it illegal for local govt to regulate guns (with the exception of no-discharge laws)...
Your best bet would be to call some CIII dealers, up here and see if they rent... I don't have any numbers for you, unfortunately...