i must at mit, this is a big job as i thought i my self before, and when you realy think wot you need to do, at the end of it all it be more easy to try and get a 2door , as you need all the inners of the qtrs and a 2door roof!
door etc, it going to cost a lot of dosh unless you got a doner 2door.
plus if you ever sell it, someone is think its tag'ed up as a 2door, it may be a problem to sell if you did.. the way you should look at it more doors are becoming a wanted car, so you best off leaveing as it is..
but your choice mate..