Is there anything I can do about the hard disk, I am sure it is contributing to the loudness as well and who knows how reliable it is after all these years. Is there some way to upgrade it to a standard IDE or SATA or CF?
I ditched the hard drives in my systems and went with CF. The easiest way is with one of the MechWare SCSI card readers, however they're no longer available from him and expensive when they pop up on ebay. You can also use something like the Acard SCSI-to-IDE bridge, that would allow you to use an IDE hard drive. Additional options exist if you're willing to stack a couple adapters, such as SCSI-to-IDE-to-SATA. Although I've never tried this personally you'll find there's users using all different manner of weird ways to connect hard drives to their Amiga's, and each one will tell you that their way is the best.
You can also add an IDE controller card.
Personally I'd avoid any of the old SCSI drives on ebay, I've bought a number of them and they tend to be flakey and near the end of their life. Your mileage may vary.
The XT bridgeboard might be fun if you enjoy messing around with that sort of thing, but of limited practical use.
