Charmoise would be ideal for ewe lambs or a charollais if you cant get hold of a charmoise
Most (well nearly every farmer I know of) who run suffolk mule ewes put a charollais tup onto them, this complements the ewe very nicely, as she has loads of milk and she is growthy and with good length and shape, also the charollais then gets rid of the black face and produces either a nice store lamb or fat lamb, very versatile!
Zwartbles would not be a good idea if you want to start a good commercial flock, they DO eat loads and loads and the people who say they dont have loads of grass/time/feed for them anyway...
Also I found when crossing them they seem to concentrate of growing legs legs and more legs, and we all know that those are chopped off and not paid for at the end of the day.
Use something that will complement your sheep! suffolk mules have loads of milk, so put something on that will grow on and flesh out on loads of milk!!

Goodluck!!
I am putting a charmoise tup to a load of welsh mule ewe lambs and crossbred ewe lambs this year and also some welsh mules shearlings, I think its 58 to the tup in total this year
