No personal experience with the Williams. They are 28/24 (higher spoke count than most) with straight gauge spokes. They are around 1670 grams. A bit heavier but stronger than neuvation.
Neuvation has a set for $390 that weigh in around 1400 grams. I've seen a few sets out at races and they have held up fine, though 20/24 hole is not a lot of spokes if you are a heavier rider.
I've been building 32h velocity hubs to vista cruiser rims. The rim is wider and and very strong, plus with 32 spokes they are bomb proof. I use sapim laser or dt revolution db spokes, 2.0/1.5 and they weigh in at 1380 grams and cost $320.
Just remember you'll probably be spending almost another $200 on good tires and glue.