No point in using a MCA20 for front left/right, as the MCA50 has two transformers, one for 3 channels and one for 2, so it's an MCA30 and an MCA20 in one chassis.
I did the same thing as Jonsher using the Anthem MCA5 as my main amp until more $ came along. I've been experimenting for a couple of years now, and currently have a Bryston 4BST driving ML SL-3's. Soon they'll be a Levinson 332 in it's place. The MCA5 has been there 5 years, and I don't see it going away any time soon.
I did the same thing as Jonsher using the Anthem MCA5 as my main amp until more $ came along. I've been experimenting for a couple of years now, and currently have a Bryston 4BST driving ML SL-3's. Soon they'll be a Levinson 332 in it's place. The MCA5 has been there 5 years, and I don't see it going away any time soon.