Any experience with single, full range drivers?

If you start with a pair of Behringer 2031A's they will certainly double as excellent stereo speakers. Install them as the manufacturer suggests unless you are being overwhelmed by in-your-face highs. The 8" woofers will do a decent job with 16' stops until you purchase a subwoofer. I'm using the 3031A's which use the type transducer that Jan Loosen mentioned earlier for the tweeter -- smooth highs with more even dispersion I think.

I'd avoid the single full range drivers as a rule though the one with the driver facing upward into a cone-type reflector may overcome some of the dispersion (beaming) issues -- that one looks interesting.

Other studio monitors should work equally well -- few of us get to audition a lot of different brands. It does not take multiple speakers to get a great sound. I've moved to six front monitors in a variety of configurations and while there is an improvement I wouldn't consider it overwhelming by any means. Adds clarity for large registrations to be sure. Whether surround helps the sound will vary with the listening room. A large carpeted area may need surround more than a smaller more reflective space.

I highly recommend placing the 2031A's on their backs, and on each side of your console,
almost eliminating direct sound, and not loosing all the high end by aiming all speakers to the wall !

I have a extremely large "sound stage", from floor to ceiling, and wall to wall, in my smallish living room .

I think one pair of 2031A's would perform well in this config,
but I'd also recommend asap, that if you use dry sample sets ,
to install a Lexicon MX400, inline with them.

That Lex. has 4 channels "two front", and also "two separate surround outputs",
if you choose to add a few inexpensive surround speakers, behind you soon.

As it is anyone's guess as to "when HW will include IR sampled Reverb", if ever,
I gave up on that after 11 years of waiting, and bought my "Lexi."

When playing my organ you have to listen specifically to the reverb, to hear it,
rather than enjoying the huge sound that you will be hearing !

Mel