I have a New Frontier Armory PCC (pistol config) in .45 ACP. They offer 9mm and 40 Cal as well. They use Glock magazines. "Build it online" and mine came in around eight bills not counting irons and RDS. It has functioned well ... so far.

You can order stuff for a pistol config, or rifle config. Stripped lowers and uppers, or complete uppers and lowers. Mine shown below - I've replace the blade with an SBA-3