Pair of StoreVirtual 3200 or 4335?

Hello,

Having trouble making our minds up what to go for it is a choice between storevirtual 4335(and possibly a pair of 4335/4730 down the line(if budget allowed)) or a pair of 3200

What we must achieve is data mirrored across two locations in an active/active scenario so if one storevirtual goes down the other continues serving the data. What is also important is auto tiering of data

System is to run on VMWare 6.0. What can one do that the other can't? Can all disks be accessed by each controller in the 3200? or is it half and half?

Thanks

Robbie