Wheelbuilding / Wheel Building / Wheel build help

Both use rubber seals just the same as the generic industrial 6000-2RS bearings in Novateccs. Bearing in mind that Planet X are dumping their remaining stock of Novatec at £34 a pair, it's hard to see why anybody would buy anything else. No 28H, but then 28 is a weird drilling anyway, no real point to it as it's not different enough from 32H to make any meaningful difference. If you're not racing, 32H f&r is fine, and if you are then you'll want deeper rims, whereupon 24H both ends will be enough for all but the biggest riders.

That's the sad truth... I really don't think spending a lot of money in fixed hubs will get you anything better than the Novatec/Planet X. There is virtually no technology in a fixed hub... it's just about good machining and Taiwanese machining is just as good as American one. Cup/cone bearings as in the Dura Ace will have a bit less drag if set correctly, but you are talking small fractions of a second over over 1 mile.
The silver Novatec even look quite nice