I recently put a $130 Sony head unit in mine, and I'm pretty happy with it. MP3 compatibility, doesn't have a bunch of motorized garbage on it, has a USB port with full support for iPod/iPhone control (rather than 'ready') and has a Aux audio port for other devices as well. Sounds pretty decent, and should do a fine job of driving pretty much any 6 1/2" door speaker you can identify.
This is the model I have: http://www.crutchfield.com/p_158GT54...&tp=5684&avf=N
No HD Radio, but I listen to my phone 99.9% of the time anyway.
For speakers, I've got a couple I'm eying, and expect this is what I'm sticking under the tree for myself. For $100 Boston Acoustics has a great set http://www.crutchfield.com/p_065S65R...5RC.html?tp=95, and I'm trying to convince myself that my head unit along has enough power to drive either these JL Audio units:http://www.crutchfield.com/p_136TR60...CXi.html?tp=95 or these Infinity Kappas: http://signature.crutchfield.com/s_1...-9i.html?tp=95. I should add that you'd have to check the mount depth and such on the JLs and the Infinities, as Crutchfield didn't list them as compatible. Sometimes this is not 100% reliable but the numbers don't lie.
I really want to like the Infinity speakers, but I've always had trouble falling 100% in love with the higher range from these. Plenty of people love them. The nice thing is, with either the JL or the Infinity, you get really close to separate component speaker performance, in a co-axial form factor.