Wise words!It's great that you are excited about your breeding program, but I would highly recommend that you slow down and not start thinking about your second female before you get your first one As a breeder you will face a constant temptation to add exciting new cats to your breeding program, but you must resist the temptation or you will be rapidly overwhelmed!!!!!
Show your male and your first female, and watch how they develop. Handle other peoples' cats, watch other peoples' cats develop, talk to other people and learn as much as you can. See what you get in your first litter. Whether or not you keep anything for yourself out of your first litter, watch your first kittens develop, at least to young adulthood, and see how they turn out. After that, you will have a bit more information about your first male and female, and clues about what they can produce. That in turn will give you clues about what you might need to add to your breeding program with your second female.
As you said, there are lots of beautiful Maine Coons out there. There will still be lots of beautiful Maine Coons out there after your first litter grows up