Subwoofer Differences and Choice

Surely VMPS should be considered.

I would take two F112s over a single F113. More even bass response in room, possibility of stereo placement. Also rumor has it that JL employees prefer two F112s as well.

Funds permitting get 2 x JL 113. Better still - throw in a fully discrete 2 channel SVS sub equalizer.

"the following subwoofers and which would you choose and why"

Of your choices, I would select the B&W 855. I know from personal experience how well the ASW 850 integrates with my system. This sub can go really deep and is easy to setup. I have heard many recommendations for the F112 or F113, but have nor heard them.