I don't have personal knowledge of yards in that area but one of our RC judges gives clinics at Gryffside Livery yard which is out that way. Might be worth googling Gryffside to see what facilities they have.
I was just going to suggest Gryffeside! You could also try Ardgowan riding centre, Faulds farm, Mid Glen, Mid Gavin, Lawmarnock, Ingliston.... I'm sure I can think of more if you're stuck! Feel free to PM me
Don't know exactly what you are looking for but I will have two stables ready in about one month. We are in Lochwinnoch, I have a small private yard for about 3 - 4 horses. I offer livery, no DIY. We have an outdoor school and great hacking. Facilities include heated bathroom with shower, catering facilities and secure tack and feed room. Give me a call. Susan 07748 907197
Ideal if you don't want a big yard and all that goes with it.