Coach Sampson you're on the right track. You can make the field multipurpose -- Baseball in spring and softball in fall (or even both during the same season). And contrary to stat's thoughts, the field will hold up. In fact, more facilities around us are going to field turf so they can get more use. The only rule is no metal cleats and no seeds. Every few years they may need to replace the right hand batters box but that's about it. I'd get a hold of the providers and let them give you guidance.
The only thing is you'll have to sell a lot of brownies to raise the funds. Good luck.