Wow !!! It was a year ago that I started this thread and it is still going.....
Follow-up: Finally was able to find a SR1911, that took about a year too..lol..
I now have two 1911's, a Sig 1911XO and the SR1911. Both are beautiful pistols, and function flawlessly. I have been using WC 47D and Mec Gar magazines with both and have had no issues. I looked at Tripp Research, they have good reviews, they also think very much about their magazines. Too rich for my blood, when the WCs and Mec Gars function well, and don't break the bank. I have been picking up several at a time from sales and specials at Midway and Brownells.
The only problem that I have encountered is continuously having to reload the magazines....
YMMV.