I'm planning on breeing clowns also. Shopping for fish again today. I've been reading everything I can get my hands on and I've learned that Clowns are all males untill the dominant/larger one becomes a female. There are a few methods of pairing:
1)One, ofcourse is to purchase a 'mated pair'. I haven't found anyone that sells them but I hear they command a high price of $2-300. ?? A little out of my league!
2)Buy a whole group, varrying in size, and let them pair off naturally.
3)Buy one very small and one larger, make them comfortable and hope for the best.
I'm using the third. I'm also planning to leave these two in the tank (60 gal.) without any other fish, for a month or two. I thought it might help. We'll see!
Best of luck! Let us know how you do.