Storm has had a lot od fun in obedience and working trials (not sure what the opporunities are for training in these disciplines where you are though?) I can also recommend agility, something Storm and I also enjoy
I'd recommend going to some sort of obedience club (if you don't already) to get the basics, and get your dog used to working with other dogs around. You can then build on that whichever direction(s) you would like to go in. You can find a list of some obedience clubs here:
www.obedienceuk.com under 'club profiles'.
Mountain rescue work...I asked a couple of years ago about it (think it was at Crufts). The people I spoke to said it was voluntary and you have to be able to go when they need you (similar to how the coastguard works?). Unfortunately my commitments are not flexible enough for me to be able to drop everything when there is a call, but if I was able to I think I would find it a very worthwhile 'hobby'.
Good Luck whatever you decide to do...sounds like your boy has landed on his feet!