HDD suggestions and RAID question

[pwcracker]

Well first I'll ask my raid question. If I setup a Raid 0 setup would it be possible to later add 2 more hdds and make it raid 10?

As for hdd suggestions, I am looking for the fastest reliable hard drives I can get. I want to setup raid 0 with two fast hard drives to get fast speeds. The size is not that important but would be considered by the price of the drive. I want to try to stay below $150 for both. Help me out guys.

 

[Emulex]

depends on the hard drive controller. raid-10 can be slower than raid 0+1

 

[pwcracker]

Ok, I'm not up on all this raid stuff. I was unaware that there was difference between raid 10 and 0+1. What I am wanting to do is buy 2 hard drives right now to setup in a raid 0 and then later down the road, say 2 or 3 months add 2 more hard drives as mirrors to the first two. Would that be possible and would I still have the increased read/write speeds or a raid 0 setup?