A double din touch screen looks good and works great. Go to sonic electronics they have a wide variety for single or double dins, and all for a great low price. I had a double din on my gt bought it from them for like 230 total and came with harness and mount.
a lower end touch screen from pioneer or kenwood would be great, all you need is the iphone adapter and it will charge and play from your phone. Usually can be had around 300-400 for the latest models. Check ebay and see features of each usually will have them bundled with the iphone adapter as well