I commute daily on a recently acquired 1985 Raleigh Kodiak and would like to build a wheelset for it, because:

• I want a dyno hub to power lights
• It sounds like fun
• It would be the next step in my development as a bike mechanic

The bike is pretty close to original, which means 27" wheels, a 5 speed freewheel, a Deore rear derailleur (looks like this one: VeloBase.com - Component: Shimano RD-DE20, Deore), 100mm front and 126mm rear dropout spacing, and cantilever brakes.

I'd like to convert the bike to 700C for better parts selection and compatibility with the other bikes I own. I'll spread the rear triangle to 130mm for parts availability too. If you can see a problem with this plan, please let me know.

I'm having a hard time figuring out what to do with the rear hub and sprockets. I'd like to change to a freehub and 7 speed cluster, but I have questions about availability and compatibility:

• Detailed specs on rear hubs are hard to come by, as is sourcing. Any suggestions on exact models that would work and where to get them? For instance, what's the difference between a Shimano Ultegra 6700 and 6800? Or a Shimano 105 5700 and 5800?
• Is putting a 7 speed Uniglide cluster on a hub designed for more sprockets just a matter of finding the right spacers? If so, how do I figure out what spacers I'll need?
• Do you forsee any problems using my existing rear derailleur and friction shifters with a 7 speed rear cluster? What would stop me from going with 8 speeds, or 9? (compatibility-wise; I don't think I'd benefit from the additional gears).
• I assume the front derailleur and chainrings will be fine, since the same chain works for 5-8 speed setups, right?