Don't worry too much about spine for shooting a fixed yardage. I have been shooting a GT 22 series (300 spine) with 155 gr tips (Insert + 125 gr point) at 27" and 42# all winter long. By the charts this doesn't spine right for me until about 75#, but who cares about the charts. They group. Personally, I would go with the bigger diameter between the two.
If You're Not Living on the Edge You're Taking Up Too Much Space
Martin/Rytera Staff Shooter
PSAA Life member, UBP Life member
PADI AOW Diver