Green Blockhead

Hello. I've been wanting to get GTA SA so I can play MTA, as I have always wanted to play it but never really got the chance. I finished GTA IV, but I believe that SA has a better roleplay game mechanic and I'm prepared to buy the game. I read that the Steam version of GTA SA is incompatible unless you change the .exe in the game directory. So that left me two options: buy the steam version or get the physical copy from Amazon (non-steam version). Does the Steam version affect anything in MTA at all? Because normally I'd get the physical copy and go from there, but we all know Steam is the best gaming platform...