Flat tappet cams are also available from Carmen Faso, he has a few grinds available.
Schneider also has a good selection.
Comp cams doesn't have much listed in their catalogs for Nailheads except for the Thumper series, but they do have the cam cores and can grind a number of their lobe profiles on it. Best bet is to look at their catalog and browse the Olds V8 section. Olds has a 1.6 rocker ratio like the Nailhead, so the lift specs would be the same.
The 'High Energy' 260H is similar to a stock cam @ 212 duration and 0.447" lift. The 'Magnum' and 'Xtreme Energy' series are more aggressive.
Another option is the roller rockers from Tom. His have a higher ratio, up to 1.9, which produce a lot of valve action (open/close rate). The TA roller rockers only have a 1.6 ratio, same as stock.
The TA roller cam, I 'hear', isn't an ideal setup due to the weight of the lifters.(?) Best to do more research first, I don't have much info.