Also, do you want to cater to the largest 'Breakout', even if the module you have bought is 1/20th of the size?
Why? I manufacture and sell over 50 'Breakout' boards, and not a single one of them was designed for use with the Arduino!
"breakout boards don't follow any noticable standards"Breakout boards for what? ICs? How many pins? Displays? Motors? Buttons? etc.If you have something specific in mind, perhaps we can help you locate it.Or get one designed, you could have a bunch built and be the distributor for it.