I'd be surprised if the existing brakes weren't perfectly fine. New pads, and you should be good to go with either 700c or 27"- those Dia-compe cantis that Miyata used on the 610 had enough range for both. Finding replacements will be, frankly, a difficult endeavor.
Re: lights- A bottle generator doesn't require you to buy batteries, and are compatible with some of the new LED lights (Lumotech IQ Cyo comes to mind). Before powdercoating, have a generator tab brazed on, and you won't have to scratch your paint with the clamp and ground screw... Also a kickstand plate is nice for a touring bike; keeps you from crushing tubes with a kickstand.