Hi - I am new on here today

Looking for some top tips, advice and experienced opinion !
I need to get sheep to eat grass and run in with 2 horses.
I would like to get a rare breed if I can and currently considering :-
Grey Faced Dartmoor
Southdown
Ryeland
Plus are ewes better or are castrated ram lambs also easy?
My CPH number is underway and I should have next week so I can then start the process to get going

There are some GFD castrated ram lambs nearby and wondered are these a good sort for what I need?
Many thanks in advance....