I'd try to find some Martin Logan Motion 12's or 40's then (if you decided you wanted towers that is). I have no idea what the bookshelf models are, but they are ribbons also and damn do they sound incredible through the midrange and top end. Loved the Motion 40's at BB's Magnolia store. I'd be interested to see what you think of the HTD Level 3 bookshelves against the EMP's though. In that $1,000 speaker shootout, everyone thought the ARX sounded a lot like the Motion 12, which says A LOT for the price of the A5. If Jon (ARX owner) ever decided to up the quality on the exterior (quite a few issues with peeling, etc I've seen) and maybe make it a slightly larger tower (I think it's kinda small isn't it?) I'd be all over it.
The ARX a2 for left and right might fit your bill nicely
I've thought about calling/e-mailing HTD and ARX to ask if they wouldn't mind me doing a review of sorts. Good pictures, notes, etc. I could bring over someone who has owned Revel Salon2, B&W 802's, RBH T2's, etc etc for a bit more educated critiquing.
Panny 65st60 / Denon X1000 / EMP e55ti / EMP e56ci / EMP e5bi / (2) e1010i