Yeah, Nautilus pullover would probably be a good exercise to hit that muscle without putting too much possible strain on the shoulders.
I've also found that pullups and dips work the hell out of that region of the body (abs, serratus, intercostal, etc, etc.) - I've found that pullups are more than just a lat/bicep exercise, and dips hit more than just pecs/delts/tris. They do wonders for much of the entire upper body.
These two exercises combined with squats, deads, bb bent rows, overhead presses, some variety of bb chest press, and heavy standing calf raises will pretty much nail everything when trying to build the foundation.