A Rubino in the front and conti gator in the back has been my standard setup for a while on a brakeless bike. I can usually get a season out of the Rubinos, and while they aren't flat proof or anything, front flats come less often for me than rears.

I can usually find Bontrager Race Lite Hardcases for pretty cheap around here ($25), and they hold up well flat/skid-wear wise. About half a season on a hardworking brakeless bike, which isn't too bad in my opinion.

As far as Rubinos in the rear? No idea. I always spring for a little more expense for a rear tire.