the cart or the horse?

I do not know those speakers but folks seem to say they are good. That leaves the source and the integrated.  I have the Bluesound and it is very good for the money. So that leaves the amp.  

By all accounts Hegel has gorgeous sounding amps but they can be pricey.  Used can be a crap shoot.  I would get something nice like a NAD C368 which works seemlessly either the Bluesound Node.  Your total spend would be $1K and transformative.  The little integrated would be light years better than the AVR.  I went on this same journey last year.  You can also try a Cambridge or an Arcam some such.  If you buy from an online retailer they will give you a nice in home trial period. Easy Peasy.  

Another alternative is to try a PS Audio Sprout.  Supposed to be a perfect little amp for your exact situation

finakky, don’t forget speaker placement  

Another option if you keep the speakers is the Schiit Ragnarok amp with their dac-card. About $1800 and has very good sound and adjustable gain which should make them match your speakers. 

i should temper my prior thoughts about a hegel or a nuprime... i did not realize the op’s speakers are a more 'niche-y' high efficiency single driver type that may indeed benefit from sweeter, lower powered tube amps... this may well be the ticket if the op is seeking a richer, fuller more saturated sound with those speakers

as others have said system synergy is critical in getting great sound out of a modest budget and speakers with very specific characteristics as the omegas seem to be (i have not heard them but i have heard many of their ilk...)

I am not happy with the sound and do not know which component to attack first. There is a lack of presence and body and the sound is well.......boring. I listen to jazz at low volumes and would like your opinion on what to work on first.

This is straight from @wavendon

He listens to jazz at low volume in a 15’x10’ room. He finds his music reproduction boring and unengaging. His Omegas are single driver (No crossover to deal with) . The driver is very high quality and very easy to drive with its 8 ohm impedance load.

A friend has Omegas (Different model but same design philosophy) he describes them as exceptionally pure , organic and musically and emotionally involving. He is using an 8 watt SET (Aric Audio) and is besides himself with satisfaction.

I believe @wavendon owns terrific speakers and has an excellent chance of achieving just what he desires (Primarily "body" and "presence"). I just happen to feel that his amplifier-preamplifier is the weak point of his current system set up, followed by the the Blue Node internal DAC. Low/modest (But high quality) power tubes to match his speakers crossoverless design.  So awesome potential for improved sound quality and connecting with those wonderful jazz musicians.

Charles

I would keep the speakers and simplify everything else. One voicing

Personally, I’d buy a used integrated - ideally something with DAC on plug-in card

With those speakers, you can be flexible on power specs

+ Used PrimaLuna (Prologue 1?)

+ Budget is almost at the very best Marantz integrated (used)

+ Used NAD, and one simplifies things even further (you aren’t far from an M33, certainly an M10) - they all act as streamers. DIRAC might contribute to listening experience in a room that size

+ With your speakers, I think the suggestion of the Luxman SQ-N150 is a lot of fun, albeit you’ll need an external DAC

+ I like the Hegel 95 suggestion above

That gives you a range of tube & ss to consider, and all of those components will last for a long time (and can be resold)

All the above subject to listening preference, but s/b easy to audition because brands are widespread

Save a little more & think about some inexpensive room treatments, if anything obvious jumps out to you

Let us know what you decide to do!

Have a great day