JWT probably the only place you wanna get cams from. I'm pretty sure the go for around $550 plus you can get the ECU tuning for a few more HP. The JWT cams are bad ass. If you havent seen it, check out the CAM test the SCC did on a classic few months ago (or check the se-r list archives). JWT came out on top by a good margin. I think the S4 cams made about 18hp and the S3's made 12-13hp.
Ya they are bad. The worst seems to be about a 1/4 in long on the edge of the lobe and about .025-.04 in deep. All the other lobes are banged up pretty good too. .01-.02in scratches here and there. I was thinking about trying to buff them out but I don't know.