Hi Scott, I'm going to go with the Hitachi as soon as I can find a good price on the net. The specs for this are:

Hitachi Travelstar 7K100 80GB 7200rpm
Mnfr# HTS721080-G9AT00
Type - 2.5"
Interface - ATA-6
Capacity - 80 GB
Buffer Size - 8 MB
Spin Speed - 7200 rpm
Max. Data Transfer Rate - 100 MB/s
Depth - 100 mm
Width - 70 mm
Height - 9.5 mm
Weight - 115 g
Average Seek Time - 10 ms
Average Latency - 4.2 ms
Heads - 4
Temperature Range - -40° to 65 ° C
Shock Tolerance - Non-operating: 1000G/1ms
Operating: 160G/1ms

I'm waiting for Yamaha to confirm to me if this will work with Tyros 2.