Having said that, I'm afraid I'm not very supportive of intermingling breeds for the sake of producing new breeds. I don't know anything about your background, but from your questions I'd infer that you are unfamiliar with breeding standards - otherwise you'd have an experienced breeder for a mentor, to whom you could direct these questions.
It sounds like you're trying to develop a curly Persian/Himalayan, or a longhair Rex, but my best advice is to have your Rex neutered. You mentioned that he has had problems with shedding, constipation, and an eye infection which almost left him blind. His medical problems alone would be a red flag to me that he may not be suited for breeding to any cat, let alone one of an entirely different breed.
Yes, I know that some of the popular breeds (including the Himalayan) originated from this kind of cross-breeding, but in all cases those were experienced breeders with years of background in their respected breeds and extensive knowledge of genetics. And even in those cases, I'm sure there were numerous problems along the way with genetic "accidents" resulting in stillborn or defective kittens.
A conscientious breeder of Selkirk Rex cats would be very unlikely to sell a whole male to anyone if they had any idea that it would be used for this kind of breeding "experiment."
I'd add that with millions of homeless cats in shelters all over the world just begging to give someone unconditional love, and dying because of the feline overpopulation problem, it seems a shame to even be thinking of introducing yet another new breed, no matter how tempting the idea might be of the potential fame and fortune.
This likely isn't the kind of answer you expected, but in good conscience I must give my honest opinion. Please get your Selkirk Rex male neutered. If he isn't spraying yet, it's just a matter of time.
(Reply expanded for publication.)