As Dusty said, GB makes ox-gard (HD, the source carry it last time I checked) and there are many other brands out there. Canadian Tire, NAPA, parts source also sell antioxidant used for automotive purposes (think battery terminals).
Noalox is just a brand name by Ideal, and you'll usually only find it at electrical wholesalers these days. Not too many folks into the aluminium wiring any more. Either way, any anti-oxidant will work just fine.