I agree with you guys about the taller piston, but even with a 7.1 rod, the piston in this case will still have plenty of skirt. Around 1.5 inches.
I would look at the piston heights in both kits too though, and figure out which one will be closer to zero deck. Sometimes, these kits come with a piston that's not optimum just because it makes it easy to put the kit together.