I think he's looking for a certain type of woman, Diamond, and everyone is allowed to have standards. He wants the one who is athletic, trim and sexy. If he chooses to use these "superficial" qualities to narrow his search, then he will get less results than if he opened up his search to include dominant women of all ages, shapes and sizes. I'm pretty sure he knows this.
I think with the porn industry today we rarely see normal sized females, all we see are these big tittied blondes with super flat stomachs, too much make up and barbie like proportions because that's what the public wants to see. Yes there are other types out there, but this is the type I see most often. I consider myself "thick." I'm in between bbw and stick thin, I like my size because I'm super cuddly and I know that I have a "sexy element" about me and I can command it when need be. Not every female you're going to come across is a size 4 or have a tiny tiny waist. It's just not going to happen. But if it is your dream to find this perfect woman who is athletic, trim, sexy, and all that jazz, then please, look for her. It might take you longer to find her because you're narrowing your search down to one type of person.
The Domme with the right mindset for you may not fit into your physical preferences in the woman, and the woman who fits the body image may be completely off in the mindset that you're looking for. Give and take a little. Get to know peoples minds before their bodies.
Being that I'm not a Domme, I can't speak for them, but there is nothing sexier than a man, no matter his shape, size, physical appearance who can think for himself and is willing to please you. I swoon over the intellectual types. I have my standards when seeking out a Dom for myself, if you can't captivate me with your words, you're an automatic out.
I truly hope you find what you're looking for, lucyboy. I somewhat agree with Diamond in that you're living in a sort of fantasy in looking for the woman who has all of these qualities rolled into one (mindset, physical appearance, personality), but if you believe she's out there, then I really hope you two find one another and click.