Subwoofer(s) for Martin Logan CLS

I'm in the market for sub or 2 to mate with my CLS2. Any suggestions and/or experiences would be appreciated. Thanks, John
I have CLS 2Z and use a Genesis Metal cone 12 sub with good results. I have also used an Audiopro B250 with good results but I felt the crossover slope with the b-250 was too gentle (it is 6db). As a result you have to have the CLS go down lower before getting out of them. With the Genesis I use a 24db Marchand crossover in between. It works very well.
I have owned cls IIZ for 7 years now.When I purchased them,the recommended choices for a sub were the Kinergetics 800,2 tower subs with 8 woofers,excellent but needing extra room and additonal amp or the Muse 18 a single high quality 25x25x25 cube with 2 woofer and included 200 watt amp.I opted for the second one.As additonal bonus they come with a personalized card for the speakers they are mated with.After a lot of experimenting with positioning of the sub( a must!) I reached a good compromise and I can say that the mating of the 2 has been a success especially considering the good but not exceptional size of my room.It cost at the time approx $ 3500,I don't know if they are still in production but are well worthed and you should be able to find them on the used market for approx $ 1500/2000.Check with Muse if the personalized card is still available for your particular series.(II different from IIa and IIz)
Jman, I had a pair of CLSIIZs and I used a pair of Vanderstein with excellent results. The 3 8" drivers in each sub were very musical and quick. They are very reasonable and I am still using them with my SL3s. Jerry