I know Robar does a Glock frame modification;
www.robarguns.com . They did a full contract for the AK State Troopers so you know they make quality products.
A aftermarket firm has alloy Glock frames, see;
www.glockstore.com or maybe
www.glockworx.com . I think CCF is a Glock frame brand too.
Morgan Boatman's
www.glockbooks.com or
www.customizeyourglock.com may aid you.
I'm not a Glocker & do not own any models. I may buy a Glock 19 Gen 04 9x19mm from Lipsey's(FDE limited series). I'm going to wait for the gun craze & hysteria to quiet down.
CF