There is a supplier in South Brisbane where I picked up a case for a client but i got mine thru auspcmarket.com.au. I'll dig out the supplier's name later tomorrow at work.

Intel make a hotswap SATA drive cage and a RAID controller, like this. 3ware's controller and cage are quite good too, the cage is very chrome and shiney. Might go well with the p160

I thought, depending on the pin configs, 64bit controllers could sit in 32 bit slots, you just don't get the throughput. Actually, I'm sure this is the case and I've done this for someone recently.