Speaker power handling

Athough the Dynaudios have some of the best drivers in the industry the Focus 140 is a midget of a speaker. I'd recommend larger speakers if you want to play loud. I'd also question your logic of having so much invested in amplification and the intention to invest relatively little in new speakers.

Those little midgets are unlikely to do anything close to realistic bass sound.

See this plot from Stereophile

You can see they have a huge hump around 80HZ and port noise/distortion in the lower midrange (red curve)

Although small, they sound surprisingly larger and for a 2 way design they are very coherent.

Dynaudio make their own "pro" drivers and are much higher quality than what most manufacturers use. So you can get away with a smaller Dynaudio than you could with almost all other models. The advantage of the small woofer is that is does a great midrange and this means the speakers have an awesome off axis response that is very even and smooth.

The lateral response is awesome

You have chosen a very good small monitor but it is not suited to your large space if you ask it to play loud (at realistic levels) - you should really look into a three way.

I'd suggest to look into ATC SCM 40's ( another budget priced studio monitor ) they can play louder and will exhibit the same revealing character that Dynaudio 140 do and may still fit you budget. However, the bass on the SCM40 will be much less boomy and may not work for you if you find yourself really happy with the 140's. (The 140 being +5db at 80 HZ is going to tend to sound like one note bass no matter what you do to try and EQ it - this is a common trait of most small ported monitors that have huge bass extension and is not meant as a specific criticism of the 140 - as other designs do this too)

I am not sure that any of the other speakers you mention are actually going to be an improvement on the 140's.

My Classe amp drove them with ease. If I could find similar performance with smoothness my search would be over.

The Paradigm's tilt upwards in the treble - if you turn the treble down then they may work better for you. If they sound harsh then you may have trouble driving them (they are like a 2 ohm load in the bass and may cause amp clipping/IMD distortion making the mids and treble harsh). Great speakers but not a smooth load.