Find the weak link to help me spend $800 or so

This is preliminary, since I am am moving to a new room, and that may dictate what I need to do. But here is my main system. I listen, by the way, to lots of different kinds of music -- presenting every demand short of techno/dance club level of bass and volume. Also, I listen to about 70% vinyl, and lots of radio. I am basically an analog guy. I do have a ton of CDs though. Finally, I am sorely tempted to throw tubes into the mix. But what and where?

Anyway, what would you do w/$800 or so audio hardware-dedicated $ (please don't recommend software -- that comes from a different pool of $. Also, don't ask me what I am dissatisfied with, because I think this system is pretty damned nice -- but I want to play with it a bit for fun). Gimme some ideas, if you care to.

System:

Analog Front end:

Giant two armed Jean Nantais Lenco L75; Arm 1: AT 1005 MkII, Denon DL103 Soundsmith Rudy cantilever contact line retip; arm 2: Grace 707, Shure M97 Era IV

Sansui TU 710 Tuner (same as TU-717 -- recently realigned and fully serviced)

Digital Front End:

Original Rega Planet
Oppo 981 SACD Player

Amplification:

Accuphase P-300
Accuphase C-200
(Both of the above recently recapped and fully serviced.)
Denon AU300LC step up device

Loudspeakers:

Thiel CS2.2

Headphones:
Sennheiser HD-600

Cables:

Nothing fancy, as I am not a believer in them, or in tweaks generally.

Any thoughts?

Thanks!