To get the steering wheel controls to work on aftermarket head units you have to get the remote module for that brand. They usually run about 50 bucks, so pucker up.
I'm partial to the pioneer premiere head units, and I've been through a TON Of head units. I even ran a couple nacamichi units back in the day and truthfully, every premiere unit I've had has impressed the hell out of me.
Not regular pioneer, but the premiere series will say "premiere" where the pioneer logo should be.