I would be willing to bet you can find a g22 police trade in or a 35 pretty cheap. When I’ve looked into top ends, I’m usually within $100 of a full Glock, so I’d say just get a whole gun.
As far as the Glock for a limited gun goes, I think you’d be just fine with it. Add Good sights, some trigger work (I like the TTI GM kit and an overtravel stop), a magwell and a frame weight if you want it, and get to shooting.