As for the biceps, you just gotta look at how they actually appear then figure out where/how you would measure and then determine on your own body where you would want them. That is what I have always done and I think I even mentioned it in the "tip" area for the forearm.Awesome stuff, great job. Will help me loads, sticky worthy imo!
EDIT: A quick question. The Reach Mark V biceps and forearms are different to the Mark VI. Thinking from off of the top of my head, I'm sure the forearm doesn't overlap the elbow (I may be wrong). Where would you recommend measuring to so that you would get an accurate and comfortable fit.