do you think it would be cheaper to buy all the parts? i saw a 13" Late 2008 Macbook logic board for a good price so i could go from there then find a case etc?
It's still not possible. Every laptop uses a different configuration for the most part which is why laptop specific hardware generally isn't available to the public other than RAM, batteries, and hard drives. Even if you could buy all the hardware there's no way to guarantee it could work properly.