Up to 60/70 it wont make much difference what you use, its not like they are going to wheel spin and loose grip..
Proper road tyre tread will give less friction so may gain you a little on top speed, but proper road tyres make a quad as twitchy as hell, whereas knoblies give a more controlable ride !
Maxxis and Kenda both make road tyres for quads, but finding something in 11" may prove impossible.