Most drive manufacturers are pretty cool when it comes to returning disks. We have a bunch that we bought from WD a while back and had to return half the batch because of errors. No problems.
My VAR recommended a product from Idealstor called iBac VIP. They had used Vranger before and were turned off by the complexity and cost of licensing. I have also heard of issues regarding support for VSS. This one is priced per host - not processor.
If interested, here is the link they...