Would you choose 1 ou 2 subwoofers for a stereo set?

Room ambience below 40Hz on some recordings, and it is nice to experience even with no bass in the track.

Totally agree with two subs over one. If you can room correct the bass you'll be smiling when you are done. Agree with most all of the above comments. good luck

Always two. They will extend the soundstage and give much greater presence.

If you are optimizing for a single sweet spot for 2 channel listening and have a lot of freedom to move the subwoofer, speakers and listener’s position around, you can make it work well with a single sub even in a very large room.

If you don’t have full flexibility of placement mentioned above, restrictions on variable phase, etc. you could add another sub to help the compromised first sub (be tactical about it though without making anything worse).

First, check out hte AM Acoustics room mode simulator.  You can use it to pick ideal locations for your listening location, speakers and subs as well as evaluate where your lowest room modes will be and how to fix them.

Personally, I'd use one, on the basis of cost, foot print and performance.  I've had nearly perfect results in some situations with a single subwoofer. Having put that sub in, dealt with room modes, added appropriate EQ and bass traps I would then ask if I needed a second. 

Looks like I'd choose 2 big subs for your room, not small ones and definitely 2.