It depends on where you want to cut your arrows. I shot 250's cut to 30" out of a very similar setup with success when I had about 225 grains up front. I would think with the weight you are considering up front, the 250's would work for you. But, if you want a 29" arrow, the 150's would probably be a better choice. In my experience, I tend to usually settle for the arrow that is weaker in spine with my longbows and get along better. Unfortunately, the only way to know is to try both! If you can't do that, my personal choice would be to go with the 250's and cut them no shorter than 30" and add the weight up front you are planning to add. Good luck!