Polymer80's Spectre 80% Glock frames is an 80% lower you can work to make it a real firearm. They recently put up a pre-sale to purchase frame and slide. This unit is comparable to Glock 17 Gen3 platform.
It also comes in either standard slide or Enhanced RMR cut slide, and is DLC coated.
They also will sell color frames, available in Flat Dark Earth and White.
The Firearm Blog also noticed that there is a Glock 19 sized frame in development at this moment
From: Polymer80 via The Firearm Blog