60" 45#@28, i draw 27" off the shelf, ff string, 125gr points...
What will be my best carbon spine?
Wood carbon aluminum? Also what is your cut to center on the bow? Listing the bow might help. From what you have listed around 50# spine would be a good place to start.
By the time you cut your arrow I think you will probably need a .600 carbon arrow.
full length?
Try the "Spine Calculator" on the 3 Rivers Archery Site. You can download the tool as well by doing a search for Stu Miller Dynamic Spine Calculator. Be warned, it is only as accurate as the numbers you put into it. Accurate numbers in, accurate numbers out.