Well, BOTH the peg-mgf and LR3 are systemic in nature.
So, for site specific, you don't gain an advantage using one over the other.
Sure, you have some increase in local binding when you shoot, yet IMO you need to shoot after working out, or do it when oyu have a pump going so that a larger concentration will be held in the muscle tissue for longer.
This is just in general.
I feel in your particular situation, the peg-mgf would be of the most bennifit for you based on you planning to use an insulin product already. LR3 and slin can produce the same type effect, and I beleive share some some of the same receptors, while MGF does not.
Choosing LR3, whil there may be a synergistic effect wuth both the slin and LR3, since your getting that effect already, I'd go with mgf.
but, there are more informed members on this board that could chime in on this for you.....
but you must click your heals 3 times while repeating "There's no place like home, There's no place like home".. (watch out for the house....)