Can Suzuki Super A grease be crossed to anything found at NAPA, Autozone, etc.?
Use any waterproof type grease. Suzuki grease isn't special, besides saying "suzuki" on the container.
Use any waterproof type grease.
Well by definition most greases are "waterproof", oil & water don't mix.
I'd recomend a "Marine" Grade grease, especially if you ride in water and/or mud a lot. It'll help keep the water (and rust) out of the bearing surfaces as long as you keep them greased.
I use Sta-Lube marine grade, it's blue and you can get it by the tube at home depot for about $7 a tube. from my experience it holds up better than other greases I've tried or cleaned out from previous owners.
You can also get Lucas Marine at home depot for about the same price.
http://www.homedepot.com/p/Lucas-Oil-14-5-oz-Marine-Grease-10320/202535871
Two greases that I swear by is the Maxima brand grease (blue), and Evinrude marine grease (also blue). I have on occasion used the Evinrude grease as gasket sealer on some non-quad applications. I get the Maxima grease at my local power sports dealers and the Evinrude grease at boating & marine supply stores.