Passive or Active Soundbar?

Hello all!

I'm currently looking for a replacement for my exising 5.1 speaker system. I purchased a new reciver just under a year ago (Denon AVR-1712) so ideally I would like to keep using that and my existing Sub. My wife does not want any satelite speakers and/or speaker wires run in the room. I'm new to the Soundbar market and I have been looking over past posts trying to find a good solution. We don't listen to much music, mostly TV and Blu-Rays (delivered via my HTPC). I just purchased a new Panasonic TC-P55GT50 and my thinking is that a soundbar would be sitting below the TV.

I'm currently looking at the following:
Atlantic Technology FS-7.1
Definitive Technology Mythos Solo Surround Array SSA-50
Definitive Technology Mythos Solo Surround Array SSA-42 (I don't think having an 8" smaller bar would be a big deal)
BIC FH56-BAR

So my questions:
Is it worth using my existing receiver and sub and go with one of these passive solutions (or is there another brand/model that I haven't seen yet)?
Should I scrap the receiver and sub and go with an active solution (Yamaha ysp-2200bl) and plug my HTPC into the sound bar and just output video to the Panasonic?

Thanks in advance!!
Edited by IowaDad - 9/22/12 at 2:27pm

Thanks for the info. My room looks something like this:





Or somethign like that. Room is pretty much a rectangle with entryway middle of the left wall and back behind the couch. I'm really new to the soundbar market and I dont know if its worth keeping the receiver and wiring up a 5 or 7 speaker system or go with a powered soundbar system and discard the Denon.

I finally have approval to purchase something from the CEO, CFO, CIO and COO (my wife... =) ). So I need to make sure the decsion is an accurate one!

Thanks!