FRIENDLY opinions. Not how you are against breeding rescues. People breed hideous starved horses all the time in South America and Mexico and im sure somewhere here in the U.S. I don't understand why everyone is coming on me for a little question on what would bring some color into my barn.
so while this statement might be true.. does your saying that really mean you consider yourself on the same level as people who do those things?
people are "coming at you" because they see you asking a question about doing something they consider unwise. no different than if you said 'i want to jump my bicycle off the roof of my house. what kind of bike has the best shock-absorption?' imo (and those of others here, it seems), that action is just as inadvisable as breeding your mare would be.
you said your mare has good conformation and a great temperament. that is wonderful, but that isn't even the minimum
requirement in my opinion of what a horse needs in order to be bred. what skills does she have that make her the best of the best and show she deserves to have her genetics passed to the next generation? what kind of show record does she have? have you tested her for the common genetic defects (often recessive) in her breed to make sure you don't continue the problem?
my suggestion to you would be to continue to love and ride your mare and not breed her. if you want a young horse, buy what you're looking for. no risk for your mare and
you know you are getting exactly what you want. also much cheaper to buy a young horse than to breed one.