If you set up the RAID array before you install the OS, the Win7 installation will install appropriate drivers. It's generally a good idea to download the Intel Matrix Storage Drivers and install them after the initial install; the system will pick the right one automatically.
Umm, if performance is bad in RAID 10 why not just use one big disk? Seriously. If what you need is a certain performance, and RAID 10 is slower than a single disk, use a single disk!
And just in case - RAID1 is not a substitute for backups. It does make the system a little more reliable, but you want to do backups anyway. RAID1 will not protect you if the system gets soaked by rain or fire extinguishers, if malware scrambles your data, if something is accidentally deleted, or any of a dozen other situations that will call for a separate backup. RAID1, by itself, will not ensure that you don't lose data.