but I want to know if it is possible to do RAID 0 on the boot drive via Win 7.
The answer is no. You can not use Windows own software RAID with level 0 on the boot/system partition. That is because to access the RAIDed information the OS has to load a driver (called ftdisk.sys in earlier versions, do not know if it still does) and to load that driver it has to access the disk.
So it is a catch 22, and can not be done. RAID 1 will work, since all information is on both disks so the operating system can boot.