I'm dont mean to take away f rom RR response only to add that I have raised sheep for years. Try to find a local sheep organization as it is a good resource to finding good stock. Just because it is cheap doesnt make it worth your time. Cross breds are a good choice for many reasons.
Years ago I had sheep that grazed with goats and they learned to browse. When I moved the sheep flock they eventually lost some of the tendency to stand on their hind legs to browse, but mine with clear everything up to with in r each of a stretched neck if I need an area stripped.
There are several breeds of sheep that are good hardy producers. If you are not intersted in the wool aspect there are those that are short or more goat like. ANd depending on feed available, twins and triplets are prefered. I used to keep records on my ewes: number of lambs lambed and weaned, problems birthing. I cullled those with lambing issues, and kept stock from the better producing ewes.
When I talked to the young man who bought 2 of my ewes a couple years ago, he was thrilled to tell me the girls wean 2 lambs a year for him with no problems. I might buy some stock back from him at some point, as I lost the ram last month and only have 2 daughters to carry on.
My suggestion also is to look at what you plan for graze and grain if any, and time of year to lamb, then decide on a breed, or mix of breeds.
Oh-- and becareful where you buy----I will not buy show stock. Nor from most auctions. Go right to the breeder.