Well due to the fact that both of these are fed from the same fuse supply and you have the windows, you should have the loom for the mirrors already there. Have you had a look inside your doors etc to check for the loom?
If it's there, you'll need the switch and the mirrors, that's all. If not, then I'll have another look. go pull your door panel off and have a look. give us a clue.
That picture looks like behind the door card (the bit that you pull off to get to the tweeter) Im pretty sure thats that bit, and nope I aint got that many wires there and certainly dont have the box thing. Does that mean its gonna be expensive?
You could be right about the location, as I nicked the pic from elsewhere, and aint too sure where it is.
If you haven't got that wiring in your door, it's not necessarily expensive, just will require a bit more effort to get the mod done. But don't be beaten this early in the game. Have a look and check what wiring is there (or not). If there are no mirrors, then there is no reason for vaux to take the wires that far up the door, they may be tied back further down inside. If it's not there, the the wiring is only 7 Wires, of which ones the red live wire off your power windows and another is an earth wire, so you've only got 5 switch wire to worry about, and you'll be able to make that up easily.
Purely out of intrest, because not having them, I don't know where, but where is the switch for these located?