Need opinions/help with RAID setup

[i2avi]

My machine is primarily for gaming and media. I'm running an i5 2500k 4.5ghz, GTX560Ti overclocked, 4GB RAM.

I'm thinking the thing that my computer would most noticeably benefit from is upgrading the storage drives. Right now, I have a 1TB 7200rpm standard Samsung HDD in the machine, and a 1TB external HDD that I could strip if needed.

What I'm considering is getting a pair of Seagate Momentus XTs and setting them up in RAID. Can I use my existing drive in this setup? What's the best RAID type for my usage? I've never dealt with RAID before.

Many of the reviews show the XTs as being faster than a 10,000RPM HDD, and just a little slower than an SSD. I think this will be a good upgrade, because my boot times and application load times are rather poor for a fairly decent gaming machine.

All opinions/tips welcome.

 

[i2avi]

• SATAIII controller integrated in Intel® P67 (B3) chipset
- Up to 6Gb/s transfer speed.
- Supports two SATAIII ports (SATA1~2) by P67 (B3) PCH
- SATA1~6 ports support RAID 0/1/5/10 mode by Intel P67 (B3) PCH

So yeah, seems like I've got 2 SATA3 ports.

I guess two XTs would cost me £90, so it's better to pay £130 for a 120GB SSD? Is that enough for Windows and a couple of games? I'd probably only load Battlefield 3 onto it, to be fair.