SFC can play NTSC games, but US NTSC games will not physically fit. This can be fixed by removing the case of either the cartridge or SFC, using an adaptor (a modified Game Genie works), or modding either the game or SFC. I recommend you buy or build an adaptor. It can play PAL games if modded.
Also, if you can find one cheap, get a Neo Geo AES. The Japanese version is cheaper and more common. The BIOS is soldered but is a standard DIP. It's not hard to mod it with a US or Universe BIOS.