Magnepan 3.7's versus 20.1's?

I have a 20X15X9' room. Back wall opens to entrance hall of house via 8 foot wide portal so room may be "bigger" in that sense.

MG20's work well I find.

I prefer tweeters on outside and have good central imaging with msuicians hanging in space (not attached to speakers). Depending on recording I can hear sounds lateral (ie "outside") the speakers.

Speakers generally "disappear".

Anyone can recommend an ideal sub for the 3.7 as I'm used to the Wilson Audio Puppy bass. Very low and dynamic and how do I connect it to my Goldmund Telos 3.9? Like the speaker but really need a sub to go down to 20hz.

Do you think a room with 12ft wide suitable for 3.7

20.7 is now available. Anyone heard it?

"Available" but not sure a dealer actually has these yet... Aynone know of an actual Magnepan dealer that has a set of 20.7's?