Just confirming what Dave says , to do a GRR you just need a landrover, the next one will suit any model from a Series 1 to an Evowhatit.
No special kit required, no comms, no 2in lift. no winch, just a packed lunch and maybe a camera. If you have it then bring some basic tools, a tow rope, jump-leads, jack and wheel wrench, the stuff you might carry day to day anyway.
...I'm trying to work out how to avoid the "convoy" look but its not easy with this route, basically a "Y" shape up a glen. I do have an idea for a bit of scenic tarmac driving to add a bit of interest for those who have been on this run before.
See you all in a weeks time !
Cheers
Gene.