I catch many, many crappie using this popper. It's tied using a 5/16" diameter head using Gary Krebb's popper jig, I've also used the Rainy's Pee-Wee popper bodies, both work well. The rubber legs are generally not necessary as I have not noticed my catch rate increasing or decreasing with or without legs.
As crazy as this may sound, just tie on a bigger "foam" dry fly, like a Chernobyl ant or hopper. I was casting to some a few years back, just because I was bored, and I didn't have any poppers. In fact, you could just about tie on any dry that will stay afloat and probably have success.
I caught my two biggest bass this year with a muddler minnow stripped on top.
However, if you do have the mini poppers, then I'd go with them first. Get a black, white and green one. Chances are any of them will work, but once in a while they get "moody".