"I saw a friend come close to flipping on a race track due to a cast wheel failure."
uh-huh. that had to suck. looks like your friend learned a valuable lesson, dont ****ing race without quality ****. what was he driving?
but, I have used cast wheels from good companies and never had problems at the track, running over 2 hours. maybe your friend HIT something at the track, causing the break, even forged wheels can crack and break man, I see it every day at my job.
more important than the forging can be the materials and actually mfg process. BBS, and VOLK, as my understanding, they cast some wheels, but do it with FEM or simulated stress analyisis, ensuing a strong wheel, without the expense of forging. a good quality cast wheel can hold up fine at a track.
anyways, if you want wheel weights:
http://www.wheelweights.net
buddy club wheels tend to be stong and lightweight, but like ADVAN, VOLK and the BBS LM series, and SSR forged untits, tend to cost out the nose.
the idea of rofging a wheel was that forging created a stronger wheel, so you can use LESS material, thus lightening the wheel. if you buy a heavy forged wheel, your wasting your time.