Developing colour negatives - Master Lab, Procolor, IQ or... ?

Hello,

I'm in a desperate search for a lab that's careful with the films it develops...
I am still using color negativ films for my fine art projects, including one on Thailand. I have so far had them developed at IQ Lab Silom. I was already not very satisfied with them : along with an occasional fingerprint, both random and mecanic scratches appear on the films, and having my cameras cleaned didn't change anything. But it got worth recently : I discovered that the last films are all stained by dozens of very small dots.
The point is those negatives will be later used for gallery exhibition prints and meant to be sold. IQ Silom acknowledged than both scratches and dots will very likely be visible on large prints (20' x 30' should be the biggest ones). Appart from the scratches, they say the small dots come from the fact they're using tap water from their building, and though they filter it, oxydation in the pipes of the building is certainly the cause of the traces left on the films. A big headeache since it means I will have to have those negatives scanned and then retouched, and IQ does not seem very commited to offer me the scans (not to mention the retouches).
Sorry for the long story...

So I was wondering if any member could tell me if this occurs in other labs, and which is the one they think would be the best bet in terms of quality of the development and proof sheets + good care taken of the films (money is not an issue, IQ being the most expensive...) :

Master Lab ?
Procolor ?
Other branches of IQ Lab ?
I see Marc Schulz posted the adress of 3 branches, I didn't know of the one in New Petchaburi rd, which is not mentioned on their brochure. has anyone tried it ?

Thanks a lot for those who would like to answer : giving my films to IQ Silom has become such a problem that I'm considering developping only my films during a trip to Europe. Not very convenient...

Bye !