Hey Tularis1,
That's ok, to be honest I've gone through similar issues where we have been unfamiliar with virtualising particular applications.
Certainly faster drives will help but it does depend on your application/load. In the case of your backups you would certainly find that using SAS drives in a RAID10 configuration would help. A RAID5 set containing SAS drives will do a lot better than a SATA array but you still have the RAID penalty to factor in. What sort of backup software are you using? For example if using a tool such as Commvault Simpana the dedupe store can get hammered and is best situated on high performance drives. Also as Mike suggested I have heard of varying performance on some of the HP RAID cards, certainly the newer G7/Gen8 generation are much better. The HP gear is also licensed so this can affect what additional features are available to you.
Cheers,
Ben Loveday