DrWho:I almost wonder if you shouldn't go with a pair of the RB-81's:
http://www.klipsch.com/products/details/rb-81.aspx
The bass is obviously going to be handled very well by your subwoofer and the RB-81's will let you put the speakers on your desk. Also, being a two-way with just one woofer, the convergence distance is going to be a lot shorter, which should really help tighten up the sound in your room.
The Heresy III is probably too big to put on your desk, and like you said, sitting on the floor isn't going to sound right either. I suppose you could always find yourself some speaker stands, but then you're just wasting space. I've also found that the sound of the Heresy seems to gel right around 10 feet...they really aren't nearfield speakers (which is how you'd have to use them).
It's a hard choice, but I would probably stick with your RF-83's for now...despite them being uber annoying to move around.
It sounds like what you need is a good pair of Forte 2's. They're a real easy speaker to carry around and will get the sound up off the floor like you need.
I tend to agree with the good Doctor here.
I own RB-81's as my main system speakers and I had the opportunity to borrow Heresy-III's for a period to compare them in my particular system (Thanks Mr. Colter!). I run the system with a pair of RW-8 subwoofers to pick up below ~50hz to whatever the RW-8 bottoms out to (something like 32hz).
Now my living room is 14x17 and I found that indeed the Heresy needed a good distance to "gel" as I found myself more comfortable with the soundstage by sitting farther away from them (well the effect was achieved by moving my stands back towards the back wall). By comparison my RB-81's stand further out into the room.
If you're talking about putting these very close to you on a desk or something, I would go with a Reference bookshelf over the Heresy. You might even look at the older RSX or new ICON series stuff too, it's more compact for the desktop. That and I speak from experience as you'd have a seriously hard time prying the RSX-5's I use with my computer rig out of my cold dead hands, (subwoofer required though, IMO of course).
Now someone might ask which did I prefer the 81's or the H-III's in my main system? Well there wasn't anything like a hands down winner, but I did prefer the H-III. Mostly for various nuanced reasons, not for any major shining victory in some department over the 81's. Sometimes I just couldn't pick one or the other. So they're pretty close IMHO. I did prefer the H-III's on stands not on the floor. While they did sound good and imaged better than I would have suspected on the floor (I had the risers) they really sparkled on stands. With the subwoofers I didn't have to worry too much about loosing the bottom end you pick up by floorstanding them, although it did dry the midrange a little. However I really like the sound of monitors on stands out in a room, so I may be biased. Also the H-III gets a few brownie points for being a very attractive looking, all wood speaker with the retro heavy black grille cloth. I like the retro look. Not that the 81's don't look cool with the copper cones with the grilles off too...
However I did think, and I could be totally wrong (remember I'm just a humble web developer not a Klipsch engineer so I don't know anything just because I work here) that the RB-81 and H-III had a similar voicing. Which I guess isn't terribly suprising; Klipsch should sound like Klipsch.