You could try looking on all their websites. If they are publically-traded companies you'll usually see an 'investor relations' tab somwhere on the site that'll give you basic financials for the company, most even have historical info and some guideance on future planning/growth.
Are you only looking for equipment companies, and/or do they have to be publically-traded companies? Try contacting some guide companies and see if they'll give you some info. Most are not publically traded, but call them up and see if they'll give you some info that might be enough for a basic economics class. Might also try something like REI - not what I'd call a 'true' outdoor company, and its a 'co-op' (or should that be a 'co-op-ted' company?
) but its an option.