You need to find out what types of ROMs or Flash you'll be programming and then get a burner. If you're dealing with the SNES I can give you some info, anything else and you'll have to do the leg work. Be warned that you may have trouble finding a programmable device that matches the pinout of the ROM you want to replace.
Yahoo has some links to manufacturers but it's missing a few:
http://dir.yahoo.com/Business_and_Economy/Business_to_Business/Computers/Hardware/Peripherals/Device_Programmers/
For your use I'd get a moderately priced programmer that will handle the devices you need. You don't need anything too fancy.
I considered getting a programmer from http://www.xeltek.com but ended up getting a more expensive unit from http://www.generaldevice.com