I wish you better luck in your speaker quest than you seem to have had in the past.

I've heard two of the speakers on your list fairly recently. Probably heard the Nola Boxers but don't remember. I don't know which you prefer, but I thought the LS50 and CM5 both sounded pretty amazing for small box speakers. Since there are no perfect speakers, you might be at this a while. haha

When you say "need more space', I am assuming that you mean that you need to have them fairly near the rear wall.

The CM5 is rear-ported, and what you probably should do is limit your choices to either front-ported or unported speakers.

I suggest the NHT Classic 2 speakers. They are sealed acoustic-suspension speakers and can therefore be placed quite close to the rear wall. They are excellent speakers.

The KEF Q300 would also be an excellent choice. It is a front-ported speaker.

I think either of those should perform quite well in that size room.

It would be cheaper to get a good tube amp and invest in some red wine and marijuana.  

Guaranteed results, more money left over to buy music. Seriously.  Far better than the best solid state amp/beer combination.

Or just pull your speakers out off the wall a little.  Or both and all of the above!

Speakers are by far the worse components in even very good stereos.  They are all full of compromise.  My rule of thumb is focus on getting midrange clarity and coherence correct and get the bass as correct as possible using setup.  There are lots of options, up to and including removing the LF driver in a 3 way speaker and covering the opening, pulling the units off the wall, driving them with push pull amps, bi-amping, bi-wiring, etc.  The amp/speaker interface is most often the most difficult to get right.  Your ears can hear around soft bass, for example, so long as it's not slow, muddy, or one note in a way that takes away from the music.  It CANNOT listen around a bad midrange.  The BODY knows better to an extent that the BODY will ask you to make a change.  

The softer bass of a good tube amp for example is often disliked by some SS amp lovers, when really it's more natural, NEUTRAL, and more coherent than the one note thump and bump (sometimes called tightness) of many many solid state amps.  Listen to a non-amplified acoustic bass, then a live amplified electric bass, then your stereo.

Seriously, if you are having this much trouble finding a speaker you like, it's time to move back stream,

Krell is your problem.

Sorry, I hate to be critical or Debby Downer.  But they make amps (especially integrated) that are good but rarely great and with most speakers pretty so-so.  I've only heard a Krell 300 shine in one system in my life, and that was in a fairly well damped live end dead end setup with Martin Logan speakers.  That same set-up in a less good room suddenly sucked the life out of music.

It can be a bit sacrilegious in the land of make believe that is American Hi-Fi Marketing, but Krell didn't actually hang the solid state Hi-Fi moon.  Open up a mid 70's Pioneer or Sansui or Marantz amp or receiver and see it filled with the same quality Japanese and American components, built better, and often including a good tuner AND a pretty good phono stage, and you suddenly understand why so few well learned audio technicians and electrical engineers own American "High End" gear.  It's not because they are tin-eared knuckle draggers.  What many American Audiophiles call arrogantly call "mid fi" is actually quite good.

That's not to crap on Krell specifically, it's that the American Hi-End market should be a little more David Hafler and Allen Wright and a little less Dan D'Augustino and Mark Levinson.  No matter what they'd have you believe, the reason the British Hi-Fi market is always booming, is because they kind of just get that you can't make things sound better by just making them bigger and shinier.

You keep swapping out speakers over and over.  You've heard Einstein's opinion on insanity, right?