Don't get a Rosewill switch...
The whole point of getting a switch is that you get gigabit transfers (requires Cat-5e or Cat-6 cabling). I'd recommend you make sure you get CAT-6 installed if you can, the cables aren't that more expensive than Cat-5 installations.. Also, CAT-6 scales up to 10 Gigabit. which is 100X faster than Cat-5.
The labor of running the cables is where the real costs are and you don't want to be doing it all over again to upgrade to faster speeds of Cat-6 cabling.
Onboard RAID vs. 3Ware RAIDI never recommend people run RAID-5 with onboard chipsets.