I dont think the heat from a 7200RPM drive would be that bad, from what I have read, they have gotten a lot better when it comes to heat generation and power consumption
And that drive should work fine. If it is within his budget though, i would recommend he get the 160GB drive. I tell laptop buyers to try and guess what size drive they will need, and then get the next largest one. I figured I would need an 80, so i got the 100. I am now wanting more space, but it has been a little over a year.