LE - I search the internet for the touchscreen. It's a 4 wire touchscreen, so that can't be a problem (i saw some topics about that). The screen i'm worried about...
I don't know if or how you could make that work but there is a shield that has a small OLED touch screen made for the arduino. See if you can find the TouchSheild Stealth in your area.
Considering that link to the screen doesn't give any information about the screen (original manufacturer, datasheet availability, etc), and that it is "only $15.00" - I personally would pass on it until I found a datasheet on how to drive it.
Given its low cost, though, I think that likely that screen is a "bare-bones" screen with a "bare-bones" driver chipset, meant to be interfaced with a real driver chip or cpu, that has RAM for a pixel buffer and a fast controller to output pixel clock data and sync pulses to draw the display from RAM.
It has a resolution of 320x240, which would be way too large to hold in the RAM of an Arduino, but maybe you could do it with some I2C RAM, or interface some 8-bit RAM with a multiplexed bus (?). You need something for the buffer, which would need to be at least 75 Kb in size (320x240x8 bit color; double or triple that if the display can do more than 256 colors, which it probably can). Your processor would then need to be able to push all that data rapidly to the display; an ATMega328 is probably not up to the task, but one of the other Atmel processors could do it (maybe a 644?). Ultimately, you are going to need external RAM (maybe) and likely a fast processor (maybe); I don't think a regular Arduino will be able to do much more than possibly a static display (like driving a TV signal).
The reason those other displays cost more is because they have that driver chipset, RAM (and interface software) already hooked up; you just have to supply the coding for the interface. I am not saying it would be impossible to hook up such a display to an Arduino (first step would be finding and mounting that special connector on the ribbon cable on a breakout board - maybe SparkFun or someplace else already have something), but it would probably be cheaper in the long run to buy one pre-made, unless your goal is to build the lower-level driver circuit/interface, of course...
