Of the recumbents, there are, I reckon, 59 which are still recognisable as recumbents. The other 40 or so are either destroyed or reduced to typically one standing stone.

You could spend a good 5 days exploring that lot plus the other non-RSC circles.

I have an Excel spreadsheet with details of these 59. Grid refs, NMR refs, dimensions, condition details and some astronomical data. If you can take Excel and want a copy, let me know.

Also, more notes here on RSCs http://www.themodernantiquarian.com/post/36258

And if you're up that way, you might want to check out some pictish stones
http://www.users.globalnet.co.uk/~stones/picts/ and elsewhere.