I just spent 45 minutes in the DTE and came up with a DECENT cloud texture in Bryce 5.  With a little more work, I could probobly get it even better.  I might do that later on.  I don't know what you are looking for as far as quality.......  well,  probably as good as you can get, but here is what I came up with in Bryce.

My advice is to really dig into the DTE and experiment no matter how experienced you are with it.  You would be suprised as to what you can come up with!

Benjamin