You should give easyGUI a try.
easyGUI is a GUI graphics software/library specifically designed to work on small(er) Embedded Systems.
No operating system needed. A basic cyclic executive is enough. 512kb of Flash should be more than OK. The library easyGUI provides is very flexible in helping to minimize the amount of Flash you need.
Supports fonts, graphics, bitmaps, touch screens and a bunch of video controllers out of the box.
Plus it is really cheap (no licensing fees, just a flat amount per seat) and comes with a PC program to design screens and generate code. The PC program takes a while to get used to but in the end it is very nice to try certain things out on the PC and then just generate and watch it run on your target.
They have a demo app on their website. It is worth checking it out.
