Dac, Preamp or Dac/Pre

I recently read the thread titled "What makes a bigger change, dac or preamp". I have a second system that I use in my study (that I listen to quite a bit) and am considering upgrading the front end. I have approximately 1k to spend. Similar to Daimbert who previously asked the question, I am using my Squeezebox Touch as my DAC/Preamplifier. From the thread it appears that the volume control is the limiting factor. My system is as follows:
a) KEF LS50
b) REL R-218 subwoofer
c) Odyssey Monoblocks upgraded (black boards, increased capacitance and transformers).
d) Squeezebox Touch into the Odyssey Amps

I will be listening to FLAC recordings or internet radio 98% of the time. I don't listen to vinyl but recently picked a cheap older turntable (Kyocera PL-601) that was in great shape to possibly listen to some of my records from high school/college (more nostalgia than anything as I have them all in FLAC) so having a phono input would be nice but not necessary.

I was leaning towards getting a preamp/dac like the NovaPre or the new Wyred Mpre which is within my price range. Would this be a significant upgrade?

My second notion was to get a better DAC such as the Wyred DAC-2 that I could pick up used for about the same price. The DAC would be used with volume control into the amps. I assume that this might be a better DAC than the integrated Mpre but would it make a difference?

My third notion was to get a tube preamp. I've never had any tube device (always ss) and thought this might be interesting. The tube preamp would likely be a vintage piece like an older CJ preamp, ARC, or other suggestions in the 1k range. My concern would be that it could be mismatched in my system.

I would also consider a solid state preamp with or without a budget DAC. For example an older Bryston preamp if continuity with my SS amplifiers would sound better.

So what are your thoughts would provide the best sonic improvement? I want to thank everyone for their input in advance.

Best Regards,
gwho