if you have the money, an avermedia HD capture card is pretty good. it can capture all the way from composite to HDMI so it is future-proof if you keep speedrunning and get into newer games.
Get an EasyCap and a mic jack 3.5mm and you are good to go. Check out my youtube channel which is "EddieEddieEddie90", I recently made a 100% Hypermode difficulty playthrough with the EasyCap.