Incline BB presses in a power rack by all means. Most influence on the upper pec's will depend on the angle of the incline bench. Might try different version or angled benched to see what suits you the best. May even have to raise the angle with a block of wood, BB plates, etc to get that proper angle. Try different hand spacings. Some guy's here, where I train, do a couple sets of wide , medium and close grip inclines (also flat benching) for their incline workout.
DB's will give a better stretch and affect the upper pec's in a little different manner than a BB will. If you can set up a pec deck for inclines than so much the better. The muscle leverage is very superior to regular fly's or cable fly's for that matter. The point of resistence in on the point of the elbows, which is desired, not on the hands. If not working with a pec deck, than cable fly's are the next best thing, way over DB fly's. Might also want to drop all other chest exercises and focus on just these incline movements. You will not lose any size in this regard.
Might try:
Incline BB...power rack, if you have one
Incline DB's
Incline Cable..prefer pec deck if you have one and can set it up correctly
two sets each (three if you must..max)...7-10 reps, twice a week. Good Luck.