How do you plan to use the SSD?
Most of the work you'll be doing relys heavily on the scratch and projects drives so will you really see its benefit?
Personally I'd go for a pair of 1Tb drives in place of the Hitachi's. The drives will be considerably faster natively and even 1Tb scratch space may not be enough for HD (if that's your intention). The new Sammy F3's would be first on my list unless you feel you need the reliability of WD's RE-series drives.
If you stick to 5 new drives plus the 3 you already have I really think you need a bigger case to cool them off. The 330 really doesn't have the cooling capacity for that many drives.
A full-mesh-fronted case like the Antec 300 or Coolermaster 590 would be better budget choices. The 590 comes with a 4-drive/120mm fan caddy and another can be added.
I'd even be tempted to go for a full Stacker 830/832 just for all the extra 120mm fan bays and room to work in.
With Win7 so close are you prepared to try it in place of Vista? It should be less system-heavy and liberate a little extra go.
Oh and does the 450HX have enough cables for all those drives?
