I would suggest buying a welder, learn to weld and sort it yourself. As you've found out, unless you pay a lot of money, most garages aren't interested in refabricating parts or doing intricate repairs.
Spend the money on a welder instead - you won't regret it and wonder how you managed without. There's plenty of advice online to help you learn.
All those areas you've treated really just need cutting out and fresh steel welding in otherwise it'll come back over time.
I know a few people have linked to how they've repaired the same section so here's mine -
http://www.sxoc.com/vbb/showthread.p...g-special-S14a post #12 onwards. It should give you a good idea of the make up of that area and one way of tackling it.