Your type of request for guidance is common on this newsgroup.
However you should copy this request to your local jewellers and their
replies will be a good indication of what you will get here.
The simplest analogy is to ask say, the Ford Motor Co. if you could be
an apprentice in the making of your new car if you come along with all
the raw materials for it.
Also Ask yourself this question and the answer you should get will be
the same as you will get here for your custom rings.
One other observation, read the last 2 weeks of postings here, youll
also find the answer.