My brother rides an ’09 Trek Fuel EX 9 and he absolutely loves it. I think it’s technically considered a trail bike (rather than XC) but he races XC with it. It’s pretty light for a full suspension, has great components, and retails right in your price range. As others have said, I would definitely try out different bikes to see what fits you best. As far as sizing goes, I’m 5’10" and ride a 19"/L frame, but I guess it all depends on the geometry, so trying different bikes/sizes and picking what feels good is your best bet. Good luck and have fun!