There is a bloke in St James (Cape Town)who has a little shop and specialises in XT's.
Unfortunately I don't have an address or anything, so I'll try to describe it to you.
If you're heading towards Fish Hoek, you'll come into Muizenberg, look for the Blue Bottle booze shop on your left.
His shop is a few m further up on your right.
It has no sign or anything, so you'll just have to look itno the shop windows to find it.
sorry, I can't remember any more than that, if you are definitely keen on using him, I can try to get a friend to get the address for you, but it may take some time.