I have a micro compact 1911 GI. i had my gunsmith put them on. they came from Brownells.
Go the Springfields Custom shop and check out the upgrades they can do for you.
http://www.springfield-armory.com/custom.php
You can turn his GI into a loaded:
1911-A1 Loaded Package
Upgrade your older 1911-A1 model with new Springfield “Loaded” features!!
Install Novak low mount rear sight, dovetail front sight, 3-Dot tritium night sights, lightweight aluminum speed trigger, extended ambidextrous
thumb safety, flat checkered mainspring housing, beavertail grip safety, delta hammer, cocobolo grips, carry bevel™ all sharp edges of pistol,
deburr pistol internally, tune extractor & ejector, recut barrel throat and polish feed ramp, titanium firing pin with heavy duty firing pin spring, tune
trigger to 4.5lb pull, parkerize or blue frame, slide & small parts as needed.