Can not directly help you with your answer, i am not a professional tool and die maker witch is who you want a answer from.
Are you planning to make the die yourself or something?
If not there is some very good options out there, i own some custom dies so have a bit of knowledge in that direction.
If looking for a sizer die, Warner tool makes a brilliant FL die, made to fit your chamber.
It sizes the whole case as a regular FL die, as it uses Neck/shoulder bushings, and makes a crisp and nice shoulder, instead of what you see in conventional bushing dies.
Made to make a perfect fit to your rifles chamber so it resizes the brass perfectly for it, and work it as little as possible.
Both the case body and neck/shoulder bushings are exchangeable so you can control neck tension, and even use other calibers with the same die body.
It has integrated headspace shims on the bottom of the die body, a very well functioning solution.
And the fit and finish is beyond any reloading tool i have ever seen.
They do use 1 1/4-12 threads though so only works with some presses, and they are not cheap.
Send in 3 cases fired 3 times in your chamber only having been neck sized to get it made, and wait for it to arrive.
Would certainly be my first choice if only looking for a sizer die.
Neil Jones also makes some excellent dies, in a lot more configurations though, so you can get matching seater, neck and FL sizer.
Threaded or inline dies. His FL sizer is quite unique too and is a work of art.
Same procedure as to get the WTC dies, although you must expect longer wait time (2-4months), but they also cost less if you only want it for one caliber.
Both of these will set you up with exactly what you need, and has more experience in the field then most.
Triebel GUntools of Germany also makes some excellent dies, that can be had as custom still need to send fired brass or reamer print though, the quality is excellent in general even for they're factory dies.
Available in 7/8-14 and 1 1/4-12 sizes.
Alternatively i guess WHidden can make you a sizer from your reamer print, but for almost the same price as a NJ die it would not be my first place to look.
If you contact either of those mentioned, i am sure they will take good care of you and get you what you need.
THe customer service is very good from my experience.
