Golf GL to GTI

How hard is it to do a motor swap in a MK2 (I believe) to make a GL to a GTI? Is this swap possible to do? I know someone that is selling his golf GL and it looks like a fun car to modify exept i don't know how hard it would be to modify. What are my options? is the suspension system the same? i believe i would be swapping into a 16v 1.8L. Can this motor handle boost?
So if people could give me some info on the car that would be great. I am good with hondas but VWs are kind of a new thing. Try to convert me!