Do NOT use the clamp on generic pedals. They move around and pose a hazard (they have all kinds of little bolt heads that can grab a shoelace, etc.
I have switched the pedals on all of my manual transmission cars to some mid-range Sparco pedals. I can't remember the model, but they are available on eBay often, usually for less than $40. I like them because they have a little pad on the left side that makes heel-toe downwhifts easier.
They install fairly easily; remove the existing rubber pad and use each pedal as a drill template. You might have to remove metal from the pedals if they have a larger footprint than you new pedals. I've never had to do this though.