Amp match for Wadia and Harbeths

I've recently taken delivery of a new Wadia 381 cd player and am now looking to find a suitable amp to partner it with my Harbeth monitor 30s.

I'm aware that some prefer using the built in volume whilst others prefer an active linestage. I'm specifically looking to hear from people who have found great amp match ups when only using the built in digital volume of the Wadia.

My budget is a max up to $7000 new or used . I listen mainly to classical music at moderate volume levels . Room is 17' x 14' x 8'.

Also as well as obviously the sound quality being paramount. I'm also looking for something with a certain iconic and classic quality that will be something I can own and be happy with for the long term. Just examples that come to mind would be say in SS , Nagra PSA (pyramid) Boulder 860, Pass Labs aleph 0 or Conrad Johnson Premier 350 or in Tubes: Mcintosh 275 , Airtight , Shindo or Viva.

I plan to audition as much as I can first ( starting first with the Nagra PSA and Mcintosh 275) but of course will not be able too for everything so any pointers and real hands on advice would be really appreciated.
audio research 100
Of the ones you mentioned I'd say the Conrad Johnson Premier 350. I did a demo on it and it was fantastic. That said my friend has the same speakers you have and he has BAT solid state pre and Manley tube amps. His sound is very nice with that. He is trying to save up to get some BAT amps as he thinks they will be much better. Those speakers are wonderful by the way, I really like my friends sound with them. I have no experience with using the cdp for volume and pre as I think I read you intend to do. Don't know if that would change my opinion or not.
I'm using a Nagra PSA with Harbeth M40.1, excellent sound, plenty of power. I using the Nagra PL-L as a pre amp so that may add a certian synergy. If you have a Nagra dealer perhaps they will let you demo both to get the feel for what a tube line stage may add.
I owned a Wadia player for almost 2 years. For the first year I used only the volume control and was convinced no preamp was needed. After all how can adding another piece be better than using the source itself? Then I added a nice preamp. To this day that addition was the single most impact any gear change has ever made in my system. You are simply holding the rest of your gear back by avoiding a preamp.

As to the rest of your question I've been using Vac gear on Harbeth Super HL-5's and they sound absolutely marvelous together.
actually, any of those fine amps you listed there will suit the harbeths.
Its all a matter of taste.
The harbeths will sound good with just about anything decent out there.
Spectron Musician III Mk2 with the V-Caps and Bybee SE Filters. I use it with my Wadia 581se. In my system, the Spectron is a good two steps up from my former Karan and Burmester amps.
I've been using a Wadia 850 directly into a ARC VT100 mk II since 2001. I've also experimented with an ARC LS-25 pre in the chain. Turns out I preferred leaving the LS-25 out of the mix. Heard better soundstaging and depth with no loss of slam, going the direct route. Adjusting dip switches in the 850 (allows its digital volume to read "over 70"; the recommended minimum level from what I have read), was simple and a good match for the VT100.
Thanks for the responses so far. 2 votes for audio research, maybe I'll check out the ref 110. The Spectron has been recommended elsewhere but I'm sorry I really hate it's styling! I'll also consider BAT. I'm soon to listen to the Nagra PSA but am concerned it maybe to dry sounding via the Wadia. My short list also now includes the Conrad Johnson LP66S/ LP125M and Aesthetix Atlas.