With Bemans I would go with 500's and if you want to stay with 125 gr. point I would start a full length to start.See how they shoot,if you want to shorten them you may need to use 50 or 100 gr. inserts.With the Beman's and most other carbons you usally have 3 to 4 spine sizes to choose from say 500,400,340 and 300.That is 4 basic spines so you adjust the spine by shortening or adding weight.They just don't come in as many spines as aluminum or wood shafts.I would try some Beman ICS 500 hunters at full length at first and go
from their.You will have the most adjustability with them if you want to stay with 125 gr. points.You have 50 and 100 gr. inserts or you can get add on weights to the back of the inserts to get your spine right.You may have to use different inserts then the ones that come with them.I use Gold tip inserts in my standard carbon arrows whether they are GT,Beman,Blackhawk or CE.