The I-Opener has a Trident Cyberblade i7 Video Chip soldered directly to the motherboard. The chip has a 230MHz RAMDAC. The 10.1" DTSN display that the I-Opener comes with has a max resolution of 800x600 at 16bpp. Since this is a DTSN display, refresh rates are not to great. DTSN displays will display a crisp image, however if the image is moving(ie a game, movie) there is noticable lag. The Cyberblade video chip uses the system ram for video ram. At 800x600@16bpp the videochip will use aprox. 2mb of the system ram if the frambuffer is full. It might be possible to replace the DTSN screen with a touchscreen as seen in this MacWorld article. Trolltouch offers various touchscreens ranging in sizes from 3" to 50". Their 12.1" model costs $1095.00, so this is a costly option.
 

Links:
CyberBlade i7
Trolltouch Touchscreens