I don't have any dealings with either of those folks , Is their any reason that your not trying one of the smiths from here on the board?
Our very own 308Nate here does awsome work (as good as I've seen) and his turn around time is realy good even on full builds assuming the parts get to him on time , several board members here can vouch for his work , hiw eb page is just bellow in my signatue box. I can't speek for Kirby first hand but he has plenty of happy customers , I've had work done to a shotgun by Shawn Carlock and I coulden't be happier.
I'm not trying to steer you away from either of you choices but just letting you know that are alot of other great builders out their.