Both the CMC-8s and CMC-10s use the same body with different capsules. They're both out of stock at the moment anyway.
Fisherking, are the CMC4s stable when you mount them on your collar? I'm thinking of getting a pair but was concerned a little about the extra size/weight.
Likwitkrazee, definitely get an SP battery box with bass-roll off. Or alternately theres the box Jon of JK labs is working on, which is what I'm aiming towards.