To fit an 80Gb drive in the H140 case I'd need a Toshiba MK8007GAH (I think) which despite being announced ages ago doesn't seem to be available to consumers to buy.
The 60Gb version is about 120 GBP so I've no idea what the 80Gb would cost. And at those prices and the risk of me messing things up, a new player sounds like a reasonable alternative.