As a long-time HK fan, from my experience, I find that the G19 is the best all-around 9mm available, and out of the .45s on the list, the Wilson CQB would be the one I'd prefer. For me, there's no .45 that shoots like a 1911, and Wilson Combat definitely hangs out at the top of the heap.
Choosing only one? Sheesh. If you sold the Wilson, you may not be in a position to buy one down the road, unless you are in an upper tier tax bracket and money is no object. By the same token, selling off the others and keeping the G19 almost seems foolish, as they are a basic commodity in the market.
Had your poll included a P7, I'd lose sleep at night trying to make a choice.