Hmmm. So no free beer eh?!
Well, while I'm here, I'll add that I've never thought of the DB8 as multi directional. Now, Antennas DIrect does have a DB8e that can aim in two diff directions. I think of that configuration as an option for the fringe case, as it's not a perfect solution for different directions due to multi-path. But that's up to the tuner to be able to sort out and hopefully give you what you want.
Having signals all around you, I think you have to figure out what channels you want from what you can reasonably get. Anything with low NM values will be a challenge; anything with an A or C could be an interference issue. That cluster just SE of you should be easy to pick up with any small UHF antenna if you have a clear view. You have some other reception possibilities to the SW obviously. I just don't think a single antenna aimed in between would have a beam width wide enough to get you solid reception. But the DB8e adjusted towards both maybe could work for you there? I'd verify that before ordering. User ADTech probably can tell you if that's an reasonable option.
Since you mentioned an HTPC, you could do a multi-antenna install and get an HD Homerun to aggregate your channels for you, no multi-path included! That takes more planning and spending though. I have two antennas feeding 3 TV's. Two of them only get channels from one antenna and the main TV has an HTPC and it tunes them all through the HDHR. It's not optimal but it works for us pretty well since we like to watch on the big screen most of the time anyway, esp since the HTPC is the DVR.