Hi 82thebar: Congratulations & welcome to the Tyros club. I (as well as many others here) purchased IBM TravelStars hard drives for our Tyros and have not experienced any problems whatsoever. I recommend the 20 gigabyte IBM Travelstar 'model 40GN' (4200 RPM) which cost me $80 seven months ago. There is also a faster (5400 RPM) more expensive 'model 40GNX' version available, but on the Tyros, I'd doubt you'd notice any benefit of the extra cost.
A few months ago, Hitachi 'took over' the IBM Travelstar line, calling it now the Hitachi Travelstar 'model 40GN'. I think this model would be an excellent choice:
http://www.hgst.com/hdd/travel/tr40gn.htm The bottom line though is that the Tyros will accept any generic 'off the shelf' laptop hard drive which meets the following criteria:
2.5 IDE
Height 12.7 mm max
40 GB max
Let us know what you end of purchasing.
Scott