Thanks for getting back to me folks, very helpful.

I contacted the hostel the other evening after Emma's response and they sent me a map with two route options from the top track to the open hillside.

If anybody else is planning to go this way and wish to get the route firmed up in the route plan then email the hostel in the first instance (http://www.greatglenhostel.com/contact.htm)and they will send you the map. They are happy to hold food re-supply parcels and also buy in gas canisters for Challengers too.

Thanks
m

P.S. Seafood and beer, see you at the Eagle then!..