March, Little Giant and Chugger aren't specifically designed for brewing either, they are just magnetically coupled high temp pumps with food-grade materials. They have been proven to work in home brewing through continued use. Lab peristaltic pumps weren't designed for brewing either but they work. These 12V pumps have been used as hot water recirculation pumps for years in solar water heating systems running 24/7, they are food grade. I have been using one for 6 months and pleasantly surprised. Personally I think March 809 pumps are over priced (look closely at yours, simple motor and no high tech materials) but they are a standard now in home brewing and even if (or should I say when) they hit $200+ people will buy them.
Just my opinion but I can recommend the 12V solar pumps, I haven't had any trouble other than mounting them as they are intended to be plumbed inline with pipe. They are small and quiet.