I have a passive rob Williams csm custom guitar. Mahogany body and neck with a thick quilt maple top and rosewood fretboard. The original pickups were Seymour Duncan's which I found too harsh. I put some fender gold lace pickups in which are better but not great with the mahogany.  
 
I am now looking for some q-tuner pickups which seem to have a great sparkle to the sound but can't find them on sale anywhere. If you know where I can buy them off the shelf in Europe preferably, that would be great.  
 
Failing that I!d like to try a full set of humbuckers in the HSS  configuration  as I currently don't have a fully humbucker guitar that I would use regularly.  Any suggestions. Only clean sounding pickups please.  Alembics pickups are not for this guitar as I want to keep it passive.  I would imagine Gibson pickups would be good for mahogany but do they do single coils or  hb in a sc case?
 
Jazzyvee

The Q-Tuners will be available again in the fall, see their website and Facebook for details.
 
As far as Gibson pups, I personally like P90s, as warm-er single coils. Most Mini-humbuckers are the same size as P90s, so you can route for one and try both.

The guitarist in my band has a strat with two P90's and that sounds great but I don't really want to start routing into the guitar. I really want to stick with what will fit in the existing holes as they are fitted to the body without a scratchplate and routing will mean I will have to have the thing re-finished again. I fancy trying out humbuckers that fit the guitar as it is.  
 
I saw the Q-tuner web site saying they were not producing at the moment but there must be some stock in a shop somewhere.... maybe...?
 
Jazzyvee
 
(Message edited by jazzyvee on August 18, 2013)

Kent Armstrong makes some nice pickups.

What about some Bartolinis in the interim? I have some in a jazz box and they sound very warm, full and not harsh at all.
 
Of course, my favorite humbuckers are the ones that came in my ES140T. It's a 1956 and the P90 was replaced with a pair of early 60s Gibson humbuckers (with the wrong patent numbers) and they just sound wonderful.

That's my fault for not understanding you meant HSS, sorry about that Jazzy. In that case, I can only suggest what Dan and Edwin have already.

You ought to try some DiMarzio noiseless single coils.  They sound great!  I have Area 67's in my G&L Legacy and they have an awesome clean jazz or blues sound through my Fender Hot Rod DeVille amp.  I also have an Area 67 in my heavy ash Fender Lead II.  
 
Stephen