Bookshelf Speakers in Built-in Bookcase

I know this topic has been touched on before, but I need some recommendations for new monitors. Unfortunately, we live in a very small house and my living room is acoustically challenged. Out of necessity, I have a system that I use both for HT and music, and the whole thing is housed in a custom-built bookcase unit that runs the length of the room. The only good news is that the built-in unit is extremely solid, built out of a mix of thick MDF and wood. You can see pictures if you click on my system. The main speakers are positioned like so:

Current system is: Linn Katan front speakers with a Linn Trikan center channel, all run in "Aktiv" mode (i.e., bi-amped with the crossover duties handled in the amp prior to amplification). They are supplemented by a Linn Accurate 221 subwoofer, and some Linn ceiling speakers in the rear. They are all run by a pair of Linn 5125 amps and an Anthem AVM-50V processor.

One problem is that the subwoofer is too far off to the right side, so it does not sound integrated very well with the mains unless you are sitting left of center. Unfortunately, there is really nowhere else to put a sub right now. My thought is that if I could find a pair of monitors that had a lower range than the Katans and still sounded good sitting on a built-in unit, then I could adjust the sub crossover point lower and alleviate the problem a bit.

I know this setup is less than ideal, but I could use some help here! I listen mostly to rock and jazz, but my kids also listen to EDM, and it needs to be good for HT as well. For right now, I'm just planning to change the mains and leave the center channel. I'll deal with that next.

With my current amplification, I can bi-amp (or even tri-amp) the mains. Budget is under $5k new or used. I have an opportunity to pick up a pair of Evolution Acoustics MMMicro Ones at a good price (under $2k). I don't know if they would be good in a built-in unit though, and they cannot be bi-amped.
I suggest you look at the Vandersteen VLR Wood's. They are designed to work best in this scenario and they sound great. The VLR Wood's are $1275.

If you are anywhere near the Audio Connection in Verona, NJ you should go have a listen. Good Luck!
IMHO, I wouldn't suggest meda funding on new mains...the end result is going to be compromised due to the set up and the speakers will never reach their potential (regardless of price).I would concentrate on what you can control: sub placement and bass.Maybe some sub guys can chime in. Good luck!
Unfortunately, I really can't move the sub. I'd like to change out the mains for some speakers that can go lower than the Katans. The Katans' frequency range is only 60Hz - 20KHz in active mode. I know I can do a lot better than that.

I saw some good deals on used B&W 805 Diamonds and Dynaudio C1's. Any opinions on those or the EA MMMicro Ones?

I'll investigate the Vandys
Thanks. I don't think I've heard any closed cabinet speakers that I've liked very much.

Also, if you look at the picture of my shelving unit, it's not of uniform depth. The counter where the speakers go sticks out much farther than the bookshelves above. This allows me to get a little space between the speaker and the wall. In fact, my current speakers are rear ported. (And, actually, Linn sold wall mounting brackets for their rear-ported monitors, so I'm not even sure that rear ported speakers can't be placed close to walls.)
Actually, I might want to retract my comment about closed cabinet speakers. On further thought, I have heard some that sound good.
I'd still love some opinions on whether any of the following speakers would work best in my room for my system (or whether I should add others to the list):

B&W 805D Diamond; Evolution Acoustics Micro One; Dynaudio Confidence C1; Scansonic MB-1; Merlin TSM.

Thank you.