Best HD config option while keeping one drive letter?

I have a situation where i can only have one drive letter. I know for best performance it is best to use separate drives for OS, swap and data. In cases where that is just not feasible what would be the best option. I have 4 -2.5 10k SAS drives right now in a raid 5. I dont need data reliability as I have backups on optical disks and external hard drives. What I want is the best performance for games and also video editing. I am looking at the Seagate 300GB 15k.5 SAS x 3 in raid 0 or the Hitachi 1GB 7K1000 Sata x3 in Raid 0 or keep the drives I have and redo in Raid 0. I am confused as to what is most important feature for those two aspects. Since I will only have one raided drive I thought the SAS ones would be better for video since they handle multiple requests better. Since it would be reading and writing to the drives at the same time. I checked out the reviews on storagereview.com and the 15k.5 sustained transfer times are amazing but in games I see the iops is actually lower then the sata drives.

So the question is can I get ligtning fast games and lighting fast vid editing with any of these 3 solutions while keeping with one drive?