For the dynamo, Son is nicer, SP is cheaper. I have both, and as
XXLHardrock mentioned above, they both work the same. I expect the son to last longer, but you never know. I don't agree with the recommendation to get a disk/though axle hub for a rim brake bike, but I already know from experience that I hate disk brakes on road bikes, so I won't ever need a hub like that. I also have shimano and sturmey archer dynamos, which are both fine for commuting, but neither would be my first choice for a long-distance bike.
For the rear hub, I like the shimano or campy cup and cone. VO Grand Cru is a nice, reasonably priced cartridge bearing hub.
Velocity rims mentioned above are a great recommendation. They have several models that would work with 38's. Alternatively, CR18 value is impossible to beat if you're looking to save some money. I have several wheelsets with mavic rims that have worked out great for me, but some people don't like them and they are in receivership right now, so maybe not the best choice at the moment.
I buy my lights, dynamos, spokes and mavic rims from Germany, either rosebikes.com, Bike24.com or bike-components.de depending on what else I'm getting in the order.
Despite having several bikes with dynamo lighting, I got a new long-distance bike last season and went with B&M AA battery lights because they're 100% as good as dynamo lights until I'm riding in the dark for more than 5 hours in a row, at which point I need some combination of lower power and more batteries, neither of which are that big of a deal. Then the 99% of the time that I'm riding when it's light out, it's super easy to swap wheelsets, and I don't have unnecessary lights on the bike.