You should be able to find Dot4 brake fluid at any major auto store or Walmart, etc. I'd pick up a name brand fluid, not the store brand.
I haven't had to replace the brakes on my wing, but from other bikes I've had I'd recommend using OEM pads. I put EBC RR pads on my Nomad and while they worked fine it sounded like a hoard of locusts every time I stopped. Before that I'd never had a problem with EBC pads.