Small block header options with O2 bungs?

I'm not sure what your asking here. So.....

Running exhaust manifolds with the 02 sensors In the head pipes is just fine.
However, no headers come stock OOTB with 02 bungs welded in the collector or the reducer. You can order reducers with the 02 bungs all ready welded in for you.
Just make sure that the 02 sensor is OK to be there as per the instructions of the maker of the device your using. In example, Edelbrock suggests that the 02 bung/sensor be in the collector and NOT the reducer of the headers.

Also, a full size starter is just dead weight. A new MP mini starter or equal is half the weight and twice the torque in starting power. Just be aware that all mini starters have the cable points in the same spot. The may be very or too close to the block.