[geeks] Looking for options to increase IOPS (Storage)

[J. Alexander Jacocks]

I've run into something of a dilemma, when it comes to storage.  I'm
doing a bunch of consulting work that requires me to test large number
of virtual machines, on a variety of OSes and installed software.  I
have a reasonable server for the virtualization (dual Xeon 2.8gHz
8-core, 10gb RAM), but I need to increase the speed of the disks that
the VMs sit on.  I have plenty of capacity (4x1tb disks, in RAID5),
but insufficient speed to run more than 8 simultaneous VMs.

So, the problem:
I have 4 3.5" SATA bays available, but SATA disks seem to be a
terrible deal, used/refurbed.  I've been looking at older 7200rpm SATA
disks, and they're all at least $0.20/gb (smaller drives are much
more!), compared to < $0.10/gb for new 1TB+ disks.
I have 6 72gb Seagate Cheetah 15k FC disks, but they're in a 1gbps
desktop chassis (Sun MultiPack-FC).  It will cost me $600 to make them
available to my server. ($200 PCIe 2gb HBA, $400 6-bay 2gbps FC
chassis)
I have 4 250gb PATA disks, but nowhere to mount them.  There is
insufficient room to install PATA/SATA bridge boards, in the case.

What would you do?  I'm trying not to waste more money than I have to,
and I'm also trying to get a reasonably good deal.

Thanks!

- J. Alexander Jacocks