Well, I'm biased, but if you can find one, I'd spend a bit more and go for a Jeff Rowland Concentra (I or II). I own the first version, and it is sensational.
Since you already have a preamp why not go the separates route with ARC? Not espousing the sound per se I have no experience with it, but it will give you flexibility plus the gear should play together well. Also never heard the Cary SLI-80 though my personal experience with Cary has been a mixed bag sound wise.
I've owned the Cary sli-80 F-1 addition & the ARC vsi55 (which may sound different than the vs55) but for my tastes I definitely preferred the Cary especially in triode mode (my speakers are tube friendly & a relatively easy load which IMO is paramount). The ARC seemed gutsier & quicker but wasn't as resolving as the Cary or quite 20/20 vision if you get my drift. I think the ARC may be more reliable tube wise (less tubes & no tube rectifiers) but if an output tube goes it might take out a resistor as the output tubes aren't fused like the Cary. I also like the fact the Cary is hard-wired point to point.
In general the Carys sound similar to the CJ stuff that you are moving away from.
I'd suggest trying the LS7 with a better amp like advertised
Ads for Rogue Monoblocks 150s or the Music Reference RM200. IMHO, monoblocks will help with soundstage/imaging by minimizing crosstalk between channels and separate power supplies. Cheers,
"Or if not even related to Carry or Audio Research, can be any brands, Would you prefers Warmth or transparency sound and why?"
As far as warmer or more transparent it would depend on you current speakers and cables along with your preference in sound. When I had my Octave and Dynaudio C1 Sigs I preferred a warmer sound (loved original Tung Sol 6550 solid black plates or SED KT88's). Then when I replaced the Dyn's with Raidho D1 and later D2's I preferred a more transparent sound (Ei KT90's and original SED 6550's). The only tube I hated was the TS KT120 with either speaker. That said that is the beauty of tubes. When I wanted to change up the sound I swapped out some tubes
Why not pick up a used ARC Classic 30 or ARC Classic 60 to pair with your preamp?
Also, if I were you, I'd forget about "warm" or "transparent," and just concentrate on what music really sounds like when you hear it live.
Have you ever seen the original version of "The Wizard of Oz?" That movie was made in the old Technicolor days ... beautiful to look at (warm), but not true to life. Everyone loves Technicolor movies ... but break away from the movie and walk outside into the environment. That's realism.
So, then Eddy, the challenge you have is ... do you want the distractions of Technicolor, admittedly with its unique attractions, or do you want realism like in real life?
I submit that what you refer to as "transparency" is more true to reality, and will be more satisfying over the long haul.
And by the way, as an owner of an ARC Classic 60 for over 30 years, I can tell you that it has its own special musicality. Not near as "transparent" as the ARC REF amps of today, but addicting nonetheless. And the ARC CL 30 is even a little sweeter sounding than the ARC CL 60.
Happy listening ...