Head over to the Android development thread for the streak 7. There are only 3 roms really to choose from. The one I use is called "custom 2.2.2" . Id absolutely use streakdroid 1.3 but I need my bluetooth keyboard. If you don't use bluetooth go that route. You can push the streak to a stable 1.4 ghz. It will fly. Otherwise, if you want a stock rom but clean go for the one I'm using. It has no overclock but everything works without a hitch. No oem junk and has a nice black icon notification bar. You will need to use a different launcher though. Easy to do. Just install from market
PERSONALLY I use vtl launcher from xda

tons of features. Pick one and ill walk you through setting it up