Get yourself a commercial breed and forget going down the rare breed road, they are more trouble than they are worth,thats why they are rare.
I was offerered a flock of Soay for nothing if I could catch them,mad as park hares.
I keep Lleyns which are about as good as you will get for easy lambing and fast growth.
I had 200% off mine this year and except for some hard feed I never had to help them at all.
Can I put my oar in here please!
There is rather a difference between rare and primitive!
Dorset Downs are on the rare breed register and yet are as commercial in type and behaviour as they come

Soays and the like, usually from Scottish islands and part of what are generally known as the Northern short tailed group are primitive, which means they are largely unimproved!......ie have tendency to live on poor land and are a bit wild in their attitude.
Rare breed is due to declining numbers and fashion not the type of sheep......The Dorset Down is an ideal beginners rare breed sheep. It is easy to catch, easy to handle, are good mothers, easy lambers if not too fat

and lambs finish at 25kg at 20 weeks off grass and milk. Added to that good fleece and a commercial shape what could be better if you want to combine keeping a breed that needs a bit of support with a good commercial carcass shape!......oh and they taste amazing!