Depending on complexity you are talking many thousands of dollars in software alone. Is this something you'd figured into the plan?
I'm not trying to discourage you, but rather to point out the tremendous investment needed to be at all competitive in such a field. I built a benchtop mill, own CAD software, and have limited access to CAM software. I cut plastic molds for casting plastic resin into (prolly similar to what you mention). It works well on the small hobby type scale. To go bigger for me would involve a significant cash outlay. I'm not even sure you can get the results you want from a "home" injection molding system, the pressures the pro ones use seem like it would be difficult/dangerous to try and replicate at home on the cheap.
Perhaps you might tell us what you have access to now in terms of tools and software, then we might be able to give some pointers towards the right direction.