The second ones have a more positive sealing area, and might be the better choice for used valve stems. But there can be too much sealing; you want there to be a slight amount of lubrication reaching the valve stem/guides. But in the case of a SBC, the guide is the head itself (cast iron) so there is always "extra" clearance.
Bottom line is I'd expect either to work. The second ones would be a good intake seal, the first ones possibly a better exhaust seal (where you need a bit more lubrication reaching them). If you were only going to get one set, the first ones in conjunction w/the small O-rings, or the second ones w/o O-rings.