CDP DAC advice

Hello,
Thanks to some great advices you guys gave me, I bought my first sound system last year. I spent most of my budget on my speakers so my setup is far from optimal. It is now time for a small upgrade.

Here's my setup :
Speakers: Paradigm Studio 100 v4
Integrated Amp: Marantz PM7001
CDP : oppo DV980h
TurnTable : Rega P1
I Also have a SqueezeBox Duet.

Even though I like my system, I feel like something's missing. The sound isn't quite what I expected. I'm sure the Oppo has a lot to do with it. I listen moslty to Jazz.

Here's my question :
Would I get a better sound upgrade by buying a good CDP or a good DAC?

I like the oppo because it plays virtually everything I feed it. I have few SACDs and a couple of DVDA.
I know a good DAC would be nice because I would be able to attach my squeezebox and my CDP but I'm afraid that the combinason OPPO+DAC won't be much of a improvement.

Keep in mind that my budget is not unlimited. I'd like to keep it in the lower 1000$.

Thanks for the advices!

Etienne