It is really hard to suggest anything without better info on your wheels...take a look at this and figure out what they are: Tire Sizing Systems

if they are 700c tires, then these: Review: Continental Grand Prix 4000s II 28mm tyres | road.cc are great and would still have some good comfort and grip while keeping a low rolling resistance.

as a thought, a new wheelset will be really really expensive (decent ones start around $350 HUNT 4Season Dura | Road Wheelset | 1696g | 21Deep 23Wide | £229 - PRE ? Hunt Bike Wheels that isn't too bad an option or some mavik aksiums, and great wheelsets can go into the many thousands of dollars). So, unless you have problems with your wheels going out of true, you can find new tires for them, and you are looking for exercise not beating land speed records, then a new set of tires might be all you need...