Went with Brake Man
products and have yet to have any trouble. My van is close to 12K LBS and I do a lot of Sierra driving plus beaucoup off roading if that even matters. My guess is that you have to do the whole kit...rotors, and pads. I would go with a larger brake system in a flash if I didn't have to switch to 17" rims. FWIW the Brakeman pads have gone quite a bit longer than stock Ford and I lost some of the brake fade I had before. YMMV. The problem with after market stuff is that you are locked in to that product, so out on the road even though you can use a stock product to get you home, you'll have to do the job over once back. Brake Man will only sell to shops which is a problem if you want to do the job by yourself. Not sure if they will sell single parts to the public; you'd have to ask.
Myself I like the idea of oversized Ford brakes.