SMS controllers on 7800

I'm thinking on bidding on a pair of Epyx joysticks for the Sega Master System that are on eBay at present. My question is: will these work on an Atari 7800 and support both buttons?

If the controllers require modification, is there someone on here who would be willing to perform the modification? I'm  not the most adept with a soldering gun and would rather pay to have someone perform the modifications.


Thanks!