I went with a 7200RPM drive since I will mostly use this drive for taking backups, etc, so I didn't want the drive to be the bottleneck. As for PE, I custom built the XP version using Bart's tools, but for Windows 7 PE, I found this great tool:
http://reboot.pro/11852/page__st__688
http://reboot.pro/11852/page__st__688