My advice is to spend enough money to get one that doesn't need structural welding. IMO, once it needs that it's on borrowed time.

You'll need to go and look at 100 shitters before you find a good one, but they are out there. Go to Ford Fair and/or National Day, there'll be plenty to choose from, but DO NOT, I repeat DO NOT be blinkered by some of the crap that 95% of sellers will spin you. Chances are the £3000 RS Turbo that you are standing infront of probably isn't 240bhp, but the owner will probably be telling you that it is.