Cheapest is best
Javelin
I have never seen workmanship of the type that you discribe come out of any of the reputable M3 companys that I have had anything to do with over the last 20 or so years.
However I have seen this sort of thing from one or two of the very cheap operators that most people in the business would have nothing to do with.
I once had an annual check to do on an aircraft that had been maintained by one of these people , if I remember correctly about 36 SB,s and a whole string of AD,s had never been done including 2 AD,s that I would put in the ultra safety critical list , one of these items the owner had a recipt for but no other paperwork.
The owner was delighted with the work untill presented with a bill IRO £3500 for the work He complaned refused to pay and when finaly court action was pending paid up.
The next time that maintenance was due he was back with the man who just rubs the aircraft with an oily rag and charges £800 for an annual dispite the fact that we had proved that he had been ripped off over a safety critical item .
I suspect that you fall into the same catorgory as the above owner , you know what good maintenance is but are just not prepaired to pay for it.
As for the parts that you are buying there is no reason not to go directly to the USA for them but you must get the supplier to provide an FAA form 8130-3 for them Remember that there may not be the market for bogus in the UK but in the USA the market is big enough to make fake aircraft bits a worthwile crime.
The 8130-3 form is your best protection from bogus parts and without it you are breaking the law.
Remember In this life you only get what you pay for , High quality maintenance is never cheap but in the long run it will save you money , but some people will never be able to see past the next maintenance bill and I can only shudder to think what price they put on there own lives and the lives of the people who fly in there aircraft.