The Alpine PDX-5 is nice, but is a bit of an overkill for the stealthbox application. The Alpine MRP-M500 would be perfect for the stealthbox and can easily be had for around $150.

It's very easy to wire things up on the X since everything you need (signals, control, and power) are already right in the trunk! You just have to be patient and careful with where you taps and how you run the wires...otherwise, you run the risk of introducing noise (most likely engine hum) into the system.