Tim_Iowa,
I'm glad that you like those brakes, but they're not relevant to the OP's situation. He needs medium or long reach brakes, and the BR-6800s are short reach.
He said he is still running 27 inch wheels on that Univega and did not convert to 700c. Short-reach may work...or they may not. Ultegra's worked on my old 1986 Raleigh and so do the Tektro's. A shop will be able to tell him for sure. If he had converted to 700c wheels then yes, he'd need long reach for sure or a caliper dropper bolt.
TenGrainBread,
Sorry but no. Dura Ace cable kits are one of the worst purchases you can make IMO. It's very nice cables/housing but makes practically no discernible difference, and the jump in price from the basic Shimano cable kits is huge. As long as the routing is is set up correctly and housing ends are opened and filed, performance from cheaper cable kits will be roughly the same. I would never advise anyone at my shop to buy these kits unless they are high-Cat racers. Even then it's unnecessary.
Opinions are great! I really like the (quote) Dura Ace cables (even though they aren't labelled as such). I can tell a difference on each of my bikes after I installed those cables. Now, are they worth an extra $15 bucks? That's a personal decision. There is no doubt they are very fine cables. Are they substantially better than standard "old fashioned" non-coated cables? Yes. Are they substantially better than the new generation coated cables? Probably not "substantial", but they do provide a crisper brake feel from my experience running those and standard on the same bikes.