Would you trust a local dealer to help you put

Steveaudio, sorry to hear that you or anyone else has bad experiences at Goodwins. I've purchased a couple of great items form them and they were very helpful. However, if ever there was a contest about bad attitude, lousy repair, unfair charges, incompetent work, arrogance and being pompous, AV. South in Tampa Fl. would beat all others combined even if the others had Johnny Boey as a tag team partner in a Texas Death Match. Best of luck.

Not to get OT but I couldn't help but notice Steveaudio's comment

A salesman at Natural Sound in Natick--who I like--& overall like the store--& is a B&W dealer--tried to convince me that I could easily power B&W M802's, with a 70 wpc tube amp (!?)

Assuming you mean N802s, I heard at least one tube amp (less than 70 wpc; 2 6CA7s per side, maybe 50-60 wpc) 802s (and 802ds) extremely well. Just sayin'...no excuse for being rude and arrogant and condescending. Like Cmalak says, you basically have 2 options; find a good dealer and pay them for the value added, or DIY thru internet/secondary market purchases. One of the reasons why B&M dealers are a little gun-shy is that there are lots of folks who use their sound rooms and their expertise to assemble a system and then buy it "on-line". Not easy at all to tell the good guys from the product pushers but one benefit of the internet is being able benefit from a wider range of "word of mouth".

This thread has morphed a little, which is ok, but I want to come back to the original premise: would you just let the dealer pick the system for 10 grand?
My view had nothing to do with whether you could trust the dealer- assuming the best intentioned dealer, with good ears, and access to a wide array of different equipment, the dealer's sonic 'taste' may still be different than yours.
I have certainly relied on dealers in the past and will continue to do so- and i believe there is value in that: in addition to benefitting from their wisdom (with the right dealer) and the ability to get access to some hard to get equipment, they can (generally, not always) provide support, like help with set-up, loaners, handling repair processing, and accepting trade-ins and trade-ups.
At the same time, I have had any number of negative experiences with dealers, including some in NYC.
Even the best dealer is sometimes constrained by the lines they do not carry.

if you are a problem solver, you don't need a dealer. learning the basics about component function and mismatches is necessary.

then trial and error will eventually lead you to a desirable result

Why not let somebody invest 10K of your money for you instead?