Best portable C&C option?

Recently started replaying C&C and Red Alert 1 and looking for a portable option to play while on the go.

I have a PSP and PS Vita so trying both of those out. I have the PlayStation 1 version loaded on both and also trying the Vanilla port for PS Vita.

Does anyone else play on a portable, what do you use? Any recommendations for playing portable, such as how to assign unit groups and overall functions with only have a joystick to use?