I'm currently running the Dell 4e/dc (Pci-e) with several Seagate Cheatahs (15k3 and 15k4 (essentially generation 3 and 4). - the Dells are essentially the same card as the LSI, but tend to be much cheaper - you need the ram, but the Battery module is not necessary (iBTTU)
The driver issue is a pain, but easily solved and I would NOT recommend flashing the card - some have been know to die and never come back - better of just to hack the drivers (easier than it sounds and I can point you to the site if you need it!)
I wouldn't buy those drives TBH - I've just picked up 3 72Gb 15k4 Cheetahs (latest gen of scsi, not withstanding the new SAS stuff - don't ask

) - drives were $75 with $18 delivery - Bargain! And they have plenty left - I can give you the model numbers and you can search them out for yourself (or mail me and I'll send you the link

)
ALWAYS get the good quality cables - I've been through several and it's hugely frustrating when you spend hours troubleshooting the rig to find it was a faulty cable! Don't be scared of 80 pin drives - the adapters are cheap and effective! (Again I can point you to my source if needs be!)
Matja - what are you using to bench - I'm struggling to get over 150mb/s sustained read on mine in HDTach