Custom Rods as a business, if you want to take the vow of poverty, welcome to the club. I don't recommend it given the atmosphere in Maryland for custom rods. Ive been doing it here for 25 years and it will never take off well enough to have a business.
I'm not sure if I've ever really seen a successful independent custom rod building business. Even in the old days when factory rods weren't the quality they are today, custom rods were offered as a seondary or add on to a business that either sold rods and reels or repaired them. I would suggest that you proceed slow and with caution. Build a few for friends, have them pass the word around and see if there is a market for them in your area. If you don't sell locally, watch out for shipping fees. The length of the rods will kill you on shipping! I wish you only the best in your endeveour. Fair winds and following seas. Capt. Bill