Your best bet for a controller is the 3ware Escalade 8506 series.
They come in 4, 8 and 12 port cards, running PCI-X 66mhz 64bit.
As for performance i dont really know, i havnt seen any tests of the new cards with many drives in raid 5, only benchy ive seen was a 2 drive Raid 1 and 0 bench, wich is rather uninterresting.
Ofcause the SCSI is more tried and tested than the SATA standard, its pretty obvious when you think about it... But for small to midrange datastorage servers, where you need _alot_ of capacity cheaply there isnt really an alternative.. Yes you can go with PATA too but i find any good reasons why to do so... the cables are much bigger and shorter, and potentially the speed of SATA is faster.
Im just about to buy some 8506-8 cards myself, and im still hoping to find a test of the raid 5 performance sooner or later. Else im gonna make them myself
3ware can be found at the following address: 3ware escalade controllers