Ross, Shimano's lower end dual pivot calipers are totally nice and will work fine. You save a bit of weight by going to the more expensive ones, and the pads might be a bit nicer, but that's all.
The recessed nut thing is likely to be an issue. If you know what you're doing it's not a big deal to drill out the frame; I've done this myself converting an old Nishiki mixte to modern brakes. Alternatively, I think Harris has a kit to convert recessed nut brakes to non recessed nut brakes.
I've lost those plastic cable stop thingys as well, and just wound up scrounging other ones off an old bike that someone was throwing away. You might want to have a look around your local co-op. Alternatively you could get some Tektro aero levers---they are super cheap for what you get, and ergonomically and functionally they are likely to be a huge upgrade over the ones you have.
Last edited by mander; 06-10-09 at 02:08 PM.