Haven't used either brand personally, but they seem to be reputable. I know Drifters in Joburg have stocked Montrails before. You could also try Hikers Paradise in Centurion, if you can get there. Haven't been to either store for a while, so not sure what they have in stock. Check out mountainmailorder.co.za, they have a pair of old style Torre GTX's on special currently. Check out
www.mammothoutdoor.co.za for some Scarpas. Let me know what you land up getting and where, since I'll be scouting around for new boots too in the next while.