BUMPFF,
When it comes to Windows, it is all about Disk Access. The best option is a 7,200rpm Hard Drive with an 8Mb Cache.
Since you have UDMA-66, you do not need to worry about getting a UMDA-100 or a UDM-133 Controller, since today's Hard Drives cannot fill the UDMA-66 Pipe.
I would recommend the Western Digital JB line of Hard Drives. In your case, either the 80Gb 800JB or the 120Gb 1200JB.
Take Care,
Richard