BP/Wing is regarded by many as "tech". It's true that to dive doubles you pretty much need a bp/w and to get deep you pretty much need doubles (plus stage bottles). However, just because tech divers use em, doesn't mean Rec divers can't or shouldn't. I know several "tech" divers ( plus a couple who are working on it) and they do more Rec diving than tech. I don't dive a BP/W, I dive a Sherwood Outback, which is very similar to the Seaquest BD. If I didn't already have a great (my opinion) BC, I'd probably be looking at a bp/w. It's extremely flexible (closest you'll ever get to one size fits all). So if you wear a large and gain (or lose) a few (or a lot) pounds, you can adjust, rather than replace.
But, it's not the be all and end all either. For your diving, minimal exposure protection, thus minimal lift requirements (in other words you don't need a lot of lead) a great BC would be a US Divers Alcyone. I don't think it's made anymore, but maybe there's something similar. My wife dives one. It's weight integrated (but doesn't have the capacity of mine), packs real small, comfortable over bare skin, about 27 lbs lift (which is more than the amount of lead she requires) and very streamlined. If they had something like it, with a bit more lift and room for more lead (ie the same unit about 30% larger over all), I'd have one in a heartbeat.
I do think the Knighthawk is similar. As mentioned I have a buddy who dives one and she loves it. I don't think it packs quite as small as the Alcyone, but it packs smaller than my Sherwood.
Since YOU have to wear whichever you choose, I'd try and convince the dive shops to let you try them each, even if just in a pool.