I bought a new SIG 1911 Nightmare Fastback Carry last week, and am extremely happy. I traded in a Kimber Custom with a 5 inch barrel for this pistol. The Nightmare shoots better for me, is more comfortable, has less recoil and is more accurate. I am waiting for a Garrett Industries holster to arrive and this will complete my new package. In doing my research before buying this pistol, I saw a number of different comments about magazine problems. I had zero issues with the stock SIG mags, Mecgar mags and GI mags. If anyone needs a recommendation for this model, you got it!
Congratulations and enjoy shooting it. For 1911, I have found these mags work well for me: Wilson Combat, CMC PowerMags and Tripp Research. I've also tried other brand mags and the issue I've experienced with all of them is the feed lip tend to spread and causing the mags not to drop freely.
I have the Sig 1911 Nightmare full size in 45 acp and absolutely love this pistol. Quality built and extremely accurate. Never had a problem with the magazines that came with the pistol nor the 7 round Wilson mag I purchase so as to carry it with a flush fit magazine. A great pistol.
Roughneck6, I ordered a Garrett Industries Silent Thunder holster and am waiting on delivery. These have a Kydex body and are lined with leather. I didn't want to have anything that would potentially mar the frame and went this route. I have a Silent Thunder holster for my Walther PPS and love it. Here is a link to their site http://www.giholsters.com