Please don't race on junkyard tires. If that's your plan, you're wasting your time even THINKING about what wheels to use. Just put some crap on the car and hang on for the ride.
I've done all my research in the realm of 195-225 width tires, but the results in THOSE sizes invariably point to smaller diameter wheels yeilding a lighter overall package.
For example: You can get 11-12 pound 15x6.5 or 15x7 wheels dirt cheap just about anywhere. Tires for those wheels are in the 19-21 pound range for a package weight of 30-33 pounds.
If you up to a 17" wheel, you'd have to spend 3x as much to get down to about 14 pounds for the wheel, and the tires (counterintuitively) are actually heavier at around 20-22 pounds. Net result is that you spend a BUNCH more money for a package that weighs at least 3-4 pounds more.
Again, don't get too worked up about this for Lemons. Cheap, durable wheels. Good tires. Unless money is no object, look at availalbe tire sizes in the "good tires" and their prices. The more common sizes will often be considerably less expensive. If you have a plethora of wheels to choose from, figure out what tire size is cheapest to run, then find wheels to suit.
Lemons South 2008 - Fail, Lemons South Spring 2009 - Fail, Lemons Detroit(ish) 2008 - Fail, Lemons South Fall 2009 - Fail, Lamest Day 2009 - Fail, Miami 2010 (Chump) - 2nd!, Sebring 2010 (Chump) - Fail, Cuba 2010 - Crew Chief, Roebling 2011 (Chump) - 8th!, Sebring 2011(Chump) - 19th!