high end speakers? ... not sure what brands/model

I too overlooked the bass. If the Paradigm monitors don't provide the bass you want that you heard at the dealers you may need to move to floorstanding speakers that go lower. Brands to hear (and try to audition) would be Revel, PSB, Dynaudio and there are many more. What sounds great to you may not sound great to others. Trust your ears.

Vintage enclosed speakers are far from good also.
At least horns can be tailored and tweaked as and when
newer better cones become available, and are easy to install.
Horns have stood the test of time, I mean how many boxed speakers from the 80's and before sound good today when compared to the latest speakers?
When one has bought a mega expensive enclosed boxed in speaker, one is stuck with its sound.
A good horn is most certainly musically comparable to any enclosed or panel loudspeaker, and in some instances are musically superior. IMHO.
To say one hates horns, is a bit like saying one hates Toyota's.

to put things in perspective, if your paradigms were a car, they'd be a honda accord--an excellent, tops-in-its-class all-arounder; more than enough car for many people. to get more perfromance and refinement, you'd need to pay a 50% premium for say, a lexus or acura. the question for you, of course, is whether the upgrade justifies the cost.
that said, if you're looking for more low end energy, i'd check out proac or naims own allae/arriva, which sound great with naim amps.

I hate Toyotas.

;-)

All I can say is don't get caught up in all the hype and always let your ears be the judge.