one suggestion I have is to make your data drive larger than your raid0. e.g. 500gb raid0 w/ 750gb data drive. use the data drive as a backup drive and storage of data that is not accessed often, e.g. music and photos.

the core i7 supports raid0 on the motherboard, since using a raid0 is much cheaper today than an ssd i would wait 6-9 months, prices of SSD's will come down and the capacity will go up. if you use SSD's or not you will still need the data drive so that is not wasted money. 2x 250gb HHD's are pretty cheap, I would go this route until you can go SSD raid0.