file placement across 3 RAIDs

Hi. Could you advice me about the best file placement in my situation. I'm preparing to move 2 databases from old machine (sql2000) to new 2005. I have 3 physical RAIDs:
[1] RAID1 - system
[2] RAID10
[3] RAID1
The best place for data files is of course [2]. But how to separate logs and tempdb? First database is Scala financial system, ~6gb, second one is automotive system (customers, parts/vehicles sales and purchases), ~3gb. I'm not sure about the read/write ratio though.