If the OP has not yet made their plans, Cruise America is probably the largest RV rental company in the U.S. Their number is 1-800-671-8042. Nice class C RV's of varying lengths with options to add needed camping equipment. However, my sister in law who has used them several times, once to tour around the Grand Canyon, will hit the closet WalMart to buy the cheapest stuff needed such as pots and pans etc. Regarding camping in the Buffalo area with a place on the lake, the best option would be Evangola State Park reserved through Reserve America's website. About 35 miles from Buffalo city center. If the OP does hit Niagara Falls there are two campgrounds near by on Grand Island about a 15-20 ride to the Falls. One is G..I. KOA and the other is Branches on Niagara. Both are reviewed on this website. Enjoy your visit and touring of the U.S.