For gaming WHDload + 030/XX Mhz + some ram (16Mb?). You don't need "real" scan-doubler for gaming on LCD TV. There is plenty of CHEAP solution to start and work really nice for gaming.
Here is good review:
https://www.youtube.com/watch?v=sryNIHhW23wI'm using SCART to HDMI and it is fantastic (for the money!)