I am a big fan of Pioneer Premier HUs. I have one in 3 of my cars and an Alpine in my truck. I definitely prefer the more laid back sound of a Pio compared to Alpine. I also use all Pioneer Elite in my home system. Great electronics.
The PDX are good amps now. When they first went to full range class D the technology was not there, but it is vastly improved.
Are you planning on using anything to fill the bottom end? Subwoofer selection can be tough for a truck, but far from impossible.
If you need any help, or have any questions, just ask. I have been doing car and home theater installations on the side for years. I am a mod on CarAudioForum.com, and part of the Tech Team (basically a glorified moderator with a lot of knowledge) on soundsolutionsaudio.com. I go by sandt38 on both of those sites as well. I can also recommend some really good online stores for the remaining items you need to complete your installation.