Go with the starter fertilizer if it is new seed or brand new grass. It needs the phos and certainly needs the higher potassium rate. A heavy nitrogen can and will cause a hindrance over the overall health of the oncoming turf. Excess top growth will not only take energy way from the immature seedlings' root establishment, but can also cause fungus of different types due to too much leaf growth going in to the winter months.
Thank you, Dad - for always being the dad that you were. You truly are my hero. You always were.