I suggest Wolff seven and eight round mags. They use ACT mag bodies and smooth, metal followers but use extra strength 11 pound magazine springs. They work with +P's, which is a good test of a 1911 magazine and are around $20 or $25. If you have a magazine with an underpowered spring and use hotter defensive ammunition you will likely end up with live round stove pipes. That is a beautiful 1911.
http://www.gunsprings.com
http://www.gunsprings.com