Subwoofer for nearfield Omega Compact Alnico Monitors setup


I just purchased the Omega CAMs and I'm driving them directly out of the RCA output of my Chord Dave.
The room is around 16sqm (172sqft) and 4m (13ft) high.
The speakers are 1.2m (4ft) from each other and from the listening position and 20cm (8inch) from the wall.

The speakers sound truly fantastic, I could describe them like bigger Utopia headphones but with much more soundstage depth and less bass.
I can't say they are too lean, the bass is there, tight and precise, just perfect for Folk Music, Jazz and even classic Rock.
But obviously moving to EDM (yes, I'm quite eclectic on the genres...) you feel that there is something missing.

I've been reading a lot about the benefits of adding a sub to a stereo setup and would like to give it a go.
I am considering subs for monitoring like Yamaha SH8S and JBL LSR310S (also because they have an XLR in which would be perfect as I would connect them to the XLR out of the DAVE).
However there is plenty of more commercial solutions (like REl, SVS etc...) and I can't figure out which direction to take.

I'm looking for a SUB that will blend in the sound of the monitors without becoming too aggressive (music ONLY, no HT for God's sake!).

Any suggestion or comment will be welcome.
doraymon
Thanks, I understand.
I think the REL Tzero MkIII is more than enough for what I need.
Small, fast and REL.
Otherwise the T/5i but much more expensive.
Thoughts?
FYI: With a 20Hz wavelength of 60 feet, I would say subwoofers are always in the near field. 
@jmolsberg  thanks for the pass diy link -- great information!  too late to compare my omegas with my SET amps instead of the pass, but i'm curious again...
@doraymon: I have both the T/zero and the T/5i, and would have to recommend the T/5i. I bought it precisely because the Tzero, while performing well for its size, just doesn’t go low enough to really satisfy with the Omegas. It’s a 6.5" driver and you can’t fight the laws of physics. The T/5i doesn’t cost all that much more but ensures that you won’t find yourself second guessing your decision should the T/zero not fit the bill.

The damping factor issue is a real one with the Omegas, which I find very susceptible to over damping. I have two First Watt amps - the F2-J, with a damping factor of about 0.5, and the SIT-3, with a damping factor of about 30. Even though 30 is not a huge number by any measure, you can still tell the difference in bass performance. Notwithstanding the other differences between those two circuits, in general I think the lower the damping factor, the better with the Omegas!