Brake light can be done yourself for about £30.
I bought a new 2 piece boot handle release for £35 off Hurdy, but they are often on e bay, or some members here have them from when they do the reverse camera mod.
Not sure about the rest, though it sounds like a lot of hassle if you have the built in aerial installed. and as there would be nothing wrong with the actual boot, I don't really think it makes much sense to change the whole thing over.