Wheel studs and spacers with Bullitt rims

I've have already searched extensively on my issue and I'm hoping to find additional info/advice. I'm using a set of oem Ford Bullitt rims on my Duster. 17 x 8 +45mm offset all around. On the front I'm going to have to run a .672 thick spacer to get to the magic 5.6 backspace dimension needed for tie-rod clearance with the 17's. I know that .672 is kind of in "no-mans-land" for spacers. Thick for slip-on but not really thick enough for bolt-on. Easiest would obviously be to install longer studs in the front and use .672 thick slip-on hub-centric spacers which I have already made. I'm second-guessing the safety of that route versus bolt-on spacers. I have already bored the center hole in the wheels for a nice fit on the stock rotor hub so the rims would be supported by the hub as well as the wheel studs. My other option would be to custom-make a set of bolt-on spacers out of billet aluminum. The Ford rims have a pocket in the back of the wheel in between the bolt holes, therefore my lug-nuts fastening the spacers to the car would not have to be below flush. I would also use grade 8 1/2-20 flathead socket cap screws threaded into the spacer from the back side for studs. Unfortunately those cap screws would only give me about .4 length of thread engagement in the spacer by the time I countersink the back side of the spacer so the cap screw heads are below flush. My gut feeling is that the slip-on spacers and longer studs would probably be just as good if not better. The other issue I am having is finding replacement wheel studs that have the proper knurl diameter and length. The ones I have knocked out are .615 diameter front and rear. Most that I find are .62-.625. Maybe the holes are slightly oversize from already having studs installed and removed? I'm also assuming that a similar length of knurl would be preferred. Some of the aftermarket studs only have about a 1/4" knurl length versus the factory 1/2".