I would ALWAYS reccomend the original hardware, buuut...
If you want one of those go with the RetroDuo. and MAKE SURE IT IS V2.
They made revisions and the second version is better than the first. Also, get some official SNES controllers to go with it because the Stock shit they give you is HORRIBLE.
Note you can only use SNES controllers, no NES controllers on either.
However, with the RetroN, you can also play Genesis games, and use controllers for ANY of the 3 systems. But the RetroN is kinda shitty.
You also MIGHT want to check these out:
NES and SNES Powerpaks.
Great way to play all those games you don't have, or those imported games you could never get here.
It is a lot cheaper than buying all the games seperately.