Thanks everyone - will have another chat with the garage and see if I can convince them that a welded repair is OK.
I would really not want to change garages. I try to do as much as I can myself but am no expert mechanic - learning as I go though . When I use a garage I need to trust them. I've had bad experiences in the past - blown Mustang 2.8 engine after a rebuild, Lotus Excel engine almost wrecked after a cam belt change and same engine later wrecked by another garage after top end rebuild. These weren't dodgy back street places either - one was a main dealer!
Stephen/David - thanks both. Will be in touch if I decide a replacement is the way forward (or insisted upon).