There's a manual for all the focusers on the FLI site:
http://www.flicamera.com/pdf/Focuser_RevC_print.pdf
There are also drawings of the standard adapters (and prices) here:
http://www.flicamera.com/adapters/index.html
I have an Atlas on the way (shipped from the USA today) for the same reason you mention, to get additional back focus distance on a GSO RC10. I also plan to use the Atlas on my FSQ-106ED. I ended up getting two standard adapters from FLI (FSQ-106ED to Atlas and Atlas to AP 2.7" for the imaging train) and I had Precise Parts make me an adapter to connect the RC10 to the Atlas.
Cheers,
Rick.