Hey Bazdog,
Two of the best places to stay would be either Aghnahoo or the Scout Hut.
Both places are used by college clubs for trips with the scout having (better) facilities.
MUSC and Hudersfield Uni Caving clubs stayed in the scout hut at easter.
Both places are within walking distance to Marble Arch Showcaves and the nearby caves on the Marlbank Scenic Loop.
If you pm me I will forward you on contact details for Aghnahoo if you like.