As far as I know the current generation of laptop hard drives that have capacities more than 500GB are thicker than the standard laptop drive bay. There may be some laptops with drive bays large enough to accommodate the 750 and 1TB laptop drives, but you'd need to double-check to be sure.
Electrically speaking a 7200 RPM drive should work - the only downside is that it will consume more power and therefore your battery won't last as long. But the thing to watch out for is heat - the faster drive will generate more heat and that could cause a problem if the cooling system in the laptop isn't up to the job.
thanks man should i just stay with the 5400rpm i am not computer savvy i only download music and watch you tube would i notice difference between he 2????