To Preamp Or Not To Preamp Vac 30/30 MkII

Hello everyone. My current system consists of Vac 30/30 MkII, Wadia 860x and Audio Physics Virgoes. I am developing an itch to upgrade by adding a preamp in the 2-5 K range used and possibly upgrading Vac to Mk III se status at VAC for $2400. Please help me decide which will have a more profound improvement and if you have a similar system what brand of preamp, interconnect and speaker cable synergy you have found to work best. I listen to mostly jazz, male and female vocals and some rock. Yhanks for your input.
I have often been challenged with the same question. I have and love the VAC 70/70 but that isn't relevant to your question. IMO, it ultimately depends on your input source (and how many) , but I lean towards having one than not. A preamp removes the raw sound, provides coherence and helps with the imaging I have found. My input source is Sonos and I have tried with/without a pre and always go back to the pre. It's easier on the ears and simply brings everything together. My pre is a First Sound tube pre and whereas not all preamps are the same, I would still prefer one in my system for the reasons I mentioned.

+1 Charles1dad on the amp and the demand for a great pre-amp. It is a great amp (I own one) and am have always been of the opinion that a pre-amp is the heart and soul of the system. Never heard the Coincident but from all reports it is very very good. Of course, you might want to consider pairing it w a VAC pre, also.
Having recently paired a Vac 70/70 Ren mk3 with a Emotive Epifania with stunning results i would say run,don't walk to buy the little brother of the Epifania,the Sira that is for sale right now.It has the remote and v-cap option.This is right in your price range.
A good friend has the VAC Signature MK II and it is excellent sounding (I've heard it multiple times over a 3 year period). You won't find it in the stated price range, not even used.The CSL can be purchased new for just over 5K, both are superb without question.
02-23-13: Endoit
Thanks so much for your input. I find that Wadia works great at moderate to loud sound levels on the volume control i.e level 20-55 straight into the VAC. At low levels 8-20 I seem to loose dynamics, debth, seperation etc. When I use the Wadia at level 100 with a moderately priced integrated tube amp using amps volume control sound improves at low levels. Any thoughts on whether Wadia just works best set at the highest level?Endoit

It is most probably a digital domain volume control in the the Wadia, use it direct into the VAC and it will sound better than any preamp if it is used in the top 25% of full output, drop it below this and you get what's called "bit stripping" 14bit 12bit 10bit resolution the lower you go, this is probably what you are hearing when you use it at low level (less that 75% full up.)
You should put a $20 Alps Blue Velvet 20kohm passive volume potentiometer on the input of the VAC, adjust it to where then you use the Wadia's remote volume within it's top 25% of full output. (and the Wadia has a balance control as well).
You will have better sound and save yourself $2-$5K on a preamp that's not needed.

Cheers George