No worries...a horse apiece. You'll end up getting more BH's, adapters, arrows, bows, etc. than that over time...especially different adapter weights. Try them all!
If I had to answer your question, I'd pick the 125 BH w/75 gr. adapter. Put the steel in the BH, there is no strength difference between a 75 gr. adapter and a 100 gr. adapter. The weakness there is at the interface between the shank and tapered head, the extra 25 grains just makes the 5 degree taper longer.
Kris
Kris