I think that 200gr Accubond has a BC of .588, I like that! Personally I wouldn't go lighter than 180gr and would prefer the heavier 200gr in such a hot 300 cartridge. I really don't see the point in going lighter unless niether would shoot accurately, and I'm pretty sure you could get a 180 or 200gr to shoot well.
A 168gr tsx will out penetrate the 200gr accubond,and will produce less recoil as well.I would have chosen the 168gr tsx myself,but the 180gr tsx shot more accurately in my rifles.A friend of mine uses the 168gr,because it is more accurate in his rifle.