need a new ecu

i think i could use a new ecu but i have no idea what to look for. I put a few mods on my 92 gt convertable, like exust system, custom made cold air intake, custom made header, and some other small mods to improve proformance, like pugs, wires ect. but with out the ecu is confused. so i need a way to upgrade this system.
if any one could help me with this i would be a great help.thanks