I think some sort of curround speaker position change would help your system, with the direct radiators front facing like that and as high as they are, you'll get more reflection off the front wall from them than anything. I think the best idea acoustically was what was mentioned above, get stands and put the speakers on either side of the couch preferably a few feet away as much as you can, and put them just above ear level, or at least closer to than your current surround speaker set up.
As far as bipolars go, I just use 2 bipolar surround speakers (def tech BPVX's), and they do a great job for full freq. surround duties & mostly make up for not having 4 surround speakers. I'll go w/ 4 surrounds in the HT someday, but I'm not in any rush w/ the lack of 7 channel material out there right now and I probably listen to 2 channel now more than anything.