Definitely get the RC Pro. Everything about it is so much better and more powerful. You can use the Tripletek as an external monitor by using HDMI on the Pro. I don't think you can use the touchscreen.
I bought a FeelWorld 10" external touchscreen monitor to use with the RC Pro. I havn't been able to use touchscreen feature which is a bummer. I guess the RC won't honor touchscreen input over HDMI. Has anyone else figured out how?