I'd pick one and practice. Kidding aside, I'm still using a polymer grip in my repurposed Limited gun shooting .40 minor. I may put a steel or aluminum grip and 9 upper when my 40 components are gone.
Has anybody bought any top ends from IFG? I maybe converting one of my stock 2 in 40 to an optic ready 9. Complete top ends are available as per their website. I was wondering if they need any fitting.