It is my understanding that you never want to run screws with a radial tire - you could damage the cords inside the tire.
As for a wheel option other than Weld, I got some really nice ones from Centerline (for the same price as Welds). The ones I got were Ventura - 15x8 with a 5" backspace (which works perfectly on my stock rear setup) The Welds I was looking at only cam in 4.5" or 5.5" bksp. I am running 275/50-15 MT Drag radials at the track, and they fit fine (well, I have already banged up my fender lips and wheel wells a little to fit other wheels, and my quads are flipped, but still fit).
Here are the ones I got - I liked the 5 spoke design, as they don't clash too much with my fronts (Y2K Cobra R's). But, they are so nice, I am debating getting another set to run up fron too (if they will clear my planned brake upgrade).
http://www.centerlinewheels.com/whee...hicle&data=18#