400 spine is spot on. Cut on contact broadheads will cause problems! You're gonna lose arrows as they pass through. If I had one suggestion. I would add 100 grain brass inserts to a standard 400 spine arrow ICS, GT, etc. Throw the weight up front, they will fly like darts.
Got my 400 FMJ's with the brass inserts. Can't wait to get the go ahead to start pulling my bow back and send these things down range! Thanks for the help!
Ended up going with the Slick Trick Viper Tricks because they were 4 for $31 on jet.com, and my physical therapy guy said I can start shooting today. Man am I happy!