Best upgradable system components for under $6K


Hello All,

I plan on upgrading my system with components that I can live with in the short term and the long term (hopefully so I don't have to keep upgrading components as I upgrade my speakers).

I currently have an NAD 356BEE integrated and while it is entry level I must admit it sounds very nice. My room is 14'8" by 20'4" and I currently have a pair of Legacy Classics (not Classic HD). My goal is to make my next big purchase on components in the $6k or less range but I would like to make it a once and for all purchase. In other words I'm looking for something I can live with for 15-20 years without worrying about upgrading.

I would prefer to stay solid state and don't mind having an integrated or pairing separates. New or used also doesn't matter as long as it is a great bang for the bucks. My ultimate goal is to one day be driving a pair of Acoustic Zen Crescendo or Vandersteen Quattro speakers. A 200wpc + consideration would be preferred but I’m flexible on that too lol.

Finally my music selection is a bit diverse. I like jazz, soft rock and new age. Some of my favorites are Dave Matthews, John Mayer, the Wallflowers and John Tesh. I value your opinions highly and would love the community's input on the best component upgrades for my $6k budget.
xerotrace
Thank you all for the feedback so far.

ZD542: great option with the Ayre combo. It looks like new the pair is around $8.5k so I bet I can find the set used closer to my $6k budget.

Illuminator: I have not heard of Moon amps pre-amps. Do you know how they compare to Ayre, for example?
Post removed 
"You might consider active speakers since at least one of the components (the amp) comes along for the ride.
Bob_reynolds (System | Threads | Answers | This Thread)"

Going with active speakers would almost certainly be a huge downgrade in sound quality. There's just no way around it. The OP is considering a Ayre/Vandersteen combo. What kind of amp in a powered speaker would be the equal of an Ayre V-5? No active speaker that I know of, at any price, has an amp that can even comes close to it. When you ask the question, who is the best designer of solid state amps and preamps Charles Hanson is going to be at the very top of the list. There's only a small handful of designers in the world that are in his league. Now look at the speaker. What active speaker is on par with a pair of Trio's? Again, there isn't one. Like Hanson with Ayre, Vandersteen is one of the worlds best speaker designers. Vandersteen speakers are all time and phase correct. Its not easy to design a speaker that way and I'm pretty sure there's only 2 companies left that build speakers this way. Vandersteen and Green Mountain Audio. Thiel died and the company is no longer making speakers and Meadowlark went out of business a few years back. You really can't substitute a Vandersteen with any other speaker. Powered speakers are going to come up way short in comparison to what the OP is considering.
I wouldn't be dismissive of every active speaker. As with all audio products there is a hierarchy and a spectrum that exists. A trusted audiogon member purchase the Avantgarde Zero active system several months ago and says it's really quite special. Based on prior experience with him I have regard for his opinion and sonic impressions. Of course you'd have to hear it for yourself, but that applies to everything audio.Is it better than Vandy and Ayre? who knows, you'd have to listen and decide.
A well designed active system will out perform an equivalent passive system every time. Actives allow for better implementation of crossovers and improved synergy between the amp and the crossover/drivers. Examples are JBL, ATC, Pass and Gradient.