Mainly just to play games like Pokemon to relive childhood memory's
I guess the 3DS is your better option. It's almost as much as the DSi XL secondhand and will get all the new pokemon games
I choose 3DS
XL. The screen size is great even for people with the worst vision. Support for the 3DS has been dying since it's release, hence why they dropped the price about a month or 2 after launch.
Match it up with a flashcart, microsd card and as many roms you can and have a ball.
You could always get the 3ds XL. It's coming out in August, I'll give you a link.
Edit: just realized this thread is pretty old.
Separate names with a comma.