As Sirius said most companies can offer you RAID.
If you simply contact their sales department it's very likely that they can offer you a solution.
RAID is very popular due to the generally adverse effect of hard disk failures.
edit:
www.tranxactglobal.com - GNAX dedicated servers with per GB bandwidth.
edit2: also check out
www.softlayer.com. They're new but they do appear to be very clued up judging by their superb responses to my pre-sales questions. They offer cost-effective raid solutions, but as Sirius said below cheaper is not always better especially when it comes to RAID. You definitely don't want a cheap RAID card.