JM Lab mini Utopia's and which sub

I use to have a two channel set-up with the JM labs mini's
The high and the mid's where great and the low can be a little better.

Now I am building a surround set with five mini's and a sub
which sub wil do? I still like te listen two channel
but surround has to go with a bang.

Will the mini's do good as a surround speaker?
and which sub can I use?

Now i hear that the Martin Logan Descent will do in bought causes a really good job, please some feedback

Thx

Alex