I'm actually not at all surprised by the radio...a lot of STXs have the AM/FM radio from the factory. Ford knows a lot of people will just go aftermarket anyway. GM does the same with Colorado Street Pak trucks.
I was considering the explorer limited wheels from an 04 or 05. I've seen them on a ranger before and they look awesome. I think I'll make a few payments on the truck first before I go looking for new wheels though lol.