Bearings probably shouldn't be the main focus on the hubs, particularly in the front wheel. I'd consider flange placement to be as important or more important.
Front bearings consume very little of your power, about 0.25w in our example. So the difference between one good set of bearings and another is going to be insubstantial. Finding a hub built specifically to decrease the bracing angle of the front wheel will probably have more benefit by lower aero drag than any change of the bearings between brands of hubs.
As RDV said, take a look at C-4 bicycle components, they have a new deep rim specific hub coming if it's not already out. It has a reduced flange spacing that both helps create a better angle for the spoke at the rim but also reduces the amount of spoke that is exposed to the wind. The hub is the FH-70DR.
If you really wanted to take it to the extreme, you could talk to Rob English about this one that he created:
http://fairwheelbikes.com/forum/viewtopic.php?f=6&t=6975
Here is a snippet of our hub review in which we discussed bearing drag:
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Notes on Bearings and drag: Since ceramic bearings became the rage a few years ago, bearing drag has been a hot topic among cyclists. Unfortunately, there doesn't seem to be much public information on just how much of a loss the wheel bearing drag contributes. According to Bicycle Science the drag of clean, lubricated, properly aligned and adjusted ball bearings is very small. The friction coefficient is ~.0015... which is the ratio of resistive force generated in the bearing divided by the load it is carrying. If you are familiar with tire rolling resistance coefficients, this functions in the same way... except that you need to multiply this force by the bearing/wheel radius to get a comparable factor. So lets say we have a hub with 15mm axle, and the bearings are on a radius of ~12mm. The wheel's radius is ~335mm, so 12/335 *.0015 gives us an equivalent rolling resistance coefficient of .000054. To give you an idea of how small this is, typical tire rolling resistance coefficient is about .005... so the bearing resistance is ~100 times smaller. Another way to look at it is that a 200lb rider+bike traveling at 25mph will lose ~0.5W from the bearing rolling resistance. And these are not fancy bearings we are talking about... just decent steel ones.
There is another major component to bearing drag though, and that is the resistance of the seals. John Swanson did some interesting coast-down tests of wheels shown here:
http://www.bikephysics.com/rails/wheel/list Aerodynamic drag was part of it, but his instrumentation was sophisticated enough to back out the bearing drag alone. Ron did the calculations on the bearing coefficients he obtained, and got an average power consumption of 0.25W for front hubs and 0.40W for the rear hubs at 25mph... or 0.65W for both wheels. Note that there was a lot of variation, but even the worst set of wheels was only ~1.3W. Since the only load in his tests was the weight of the wheel we'd consider these values additive to the 0.5W determined above... so typical losses are about 1.2W total. Though the losses in this test would capture any effects of misalignment or preload in the unloaded state, we should point out that under typical loads these factors can result in additional friction.
Does this mean that bearings don't matter? We wouldn't say that. Instead we'd emphasize that the most important factors are cleanliness, adequate lubrication, alignment, and adjustment. If any of these are off, then the drag can be much higher. Even though smaller bearings might have lower resistance in an ideal world, larger bearings (higher load rating) will be more tolerant of un-ideal situations, probably resulting in a lower practical resistance in addition to a longer life span. If your typical hub set in good condition is only consuming ~1W then be realistic about how much improvement is possible. The added expense of ceramic bearings and the added hassle of having light seals and grease (which probably will result in quicker bearing contamination and more frequent replacement) may not be worth it.
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If you'd like to read the whole thing you can find it here:
http://fairwheelbikes.com/forum/viewtopic.php?f=65&t=6940