It sounds like you are just starting to have fun!
700c and 29's are the same size.
Hybridbkrdr pretty much covered the options. I also agree with him about the Deore (135 mm dropouts) and Tiagra hubs (130 mm dropouts). I rode fully loaded across the country on a set of Tiagra 32 spoke hubs. After several more years of hard use the wheels finally gave up the ghost. However, it was not because of the hubs!
I would also look at the Mavic 319 and 719 rims. Actually, the Mavic 119 rims are decent rims at a good price. The Mavic 119 came as OE on Cannondale's touring bikes for a number of years. My wife has been using a pair on her Cannondale for about 10,000 miles. This included the cross country trip, and several shorter tours..
The LX hubs are hard to find, and even though there is some controversy about the Shimano XT hubs; I believe they are a good hub. I prefer the LX, but didn't hesitate to use the XT when I could not find any LX's. My daughter and I have been running XT's on our touring bikes for many miles.
We run the following components on the 6 touring bikes we have in our family:
Hubs- (1)Ultregra, (1)105, (2)XT and (2)LX, All 36 spoke
Rims- (3)Velocity Dyad, (1-26")Alex Adventurer, (2)Mavic 119
Spokes- (3)Wheelsmith double butted on the wheels I had built.
We generally don't run tires much wider that 32 mm, but ocassionally I'll go to a 35mm tire. I feel for riding mostly on roads, 32 mm are more than adequate. Even for some unsurfaced roads and trails I found 32 mm tires are OK. On a tour a couple of years ago part of our route, about 400 miles, was on unsurfaced roads and trails. The 32 mm tires worked well.
All of these components have performed well.
A good place to get wheels built for a very competitive price is Universal Cycle in Portland, Oregon. They do an excellent job and their customer service is top notch.
Go to their Custom Wheelset Builder, and pick out the components you want. The prices with the build seem lower than just the cost of the components.
http://www.universalcycles.com/wheelkit.php