You should be fine when upgrading your processor and motherboard to not have to do anything with your hard drive/operating system. Windows, since XP has been plug and play for the most part.
To answer your question about socket type, it is important to match your socket type up with the CPU that you buy... IE, if your chip is a 1366 then yes you get a 1366 mobo. Asus is a good brand.
I'd go with the i7.
