GLV's got it right, your "new" stance is indeed the Chapman, ocassionally called Modified Weaver, named after Ray Chapman, former Marine and cop, one of the early dominant forces in the practical shooting world. He currently heads the Chapman Academy of Practical Shooting.
Massad Ayoob outlines this technique in Stressfire and teaches it in his LFI-1 course, which I recently took.
A true Weaver stance has strong side arm slightly bent, elbow down.
The Isosceles (both arms straight out) stance lends itself redilty to firing from a crouched position behind medium-height cover and to covering a much wider field of fire without having to move one's feet than either the Weaver or Chapman stances. This stance was all but an unknown and was certainly not in vogue with top-level IPSC shooters until 1983 when Rob Leatham showed up to the IPSC World Shoot VI and used it, handily beating everyone. Other shooters thought it was an oddity and marveled at just how good he could be if he only learned to shoot "properly" with the Weaver/Chapman techniques.
Rob persisted and drove the point home by cleaning up at World Shoot VII and VIII in '86 and '88. Since then, the stance has become the technique of choice. The irony is that it was originally developed as a defensive shooting technique, but since it's effective adaptation to compeditive shooting, IDPA now dismisses it as a "gamesman's technique".
As to which one of the three is "better", the answer is the one you personally shoot best with. Try all three and decide for yourself.
You sound like you have one of the most common beginner shooting problems known to man, the flinch. You are setting off a controlled explosion in your hands, the natural human instinct is to shield your eyes and brace yourself. The only cure for this is lots of practice and a consious effort to supress it. You are going to flinch no matter what, but the idea is to have it be a REACTION to the gun going off, not in ANTICIPATION of it. In other words, hold the sights on target and SQUEEZE the trigger until the gun goes off and surprizes you. By the time your brain responds to the bang and causes you to flinch, the bullet's long gone and you can no longer affect it's path.
I would also suggest practicing trigger control and marksmanship with a small-caliber handgun and then moving up. I personally believe that one of the biggest mistakes that can be made is to give a novice shooter (particularily a small-statured female) a large-caliber weapon to start with. Every possible problem, fear, or discomfort they might have is going to be intensified to its worst. A .22 is inexpensive to buy and feed, and great for practicing technique. My suggestion would be Ruger's variant on the Mark II, the 22/45. This gun, in a bull-barreled variant, has an overall size and weight similar to a full-sized 1911 and has a polymer grip specifically designed to mimic the overall size, shape, angle, and control placement of a 1911-style .45, hence the designation 22/45. For $300 plus $40 to a gunsmith to touch up the trigger, you get a pistol that is the perfect raining companion to your 1911, is cheap to shoot, costs a fraction of what a .22 conversion for your 1911 would cost, and can put off-the-shelf CCI Mini-Mags into a half-dollar at 25 yards all day long. Even though I've been shooting for years, I still take the 22/45 with me almost every time I go to the range and run a box through it to "settle down" before I pull the bigger toys out of their cases.
You also would likely benefit from some tilt stability in your shooting stance. Shooting with your left index finger on the trigger guard doesn't lend you much stability and costs you time on follow-up shots. I would suggest Ayoob's wedge technique. Wrap your left hand around the front of your right, as if you were going to put your finger on the trigger guard (last three fingers tight under the guard) and then wrap that left index finger UNDER the trigger guard, with it's tip in the notch between the index and middle fingers of your right hand. Grip TIGHTLY. With this grip, the web of your hand is pushing the muzzle downward and your left hand is pushing it upward. The opposing forces tend to keep the gun stable. In the same manner, when shooting Weaver stance, that is, with your right arm slightly bent, elbow almost straight down (not to the side), your right arm is pushing forward and your left is pulling back. Your feet should be about shoulder width apart, left leg out front, knees bent, slight crouch forward. In this position, you're locked in. You and the gun cannot be easily moved back and forth, up and down, side to side, or tilted. It makes your shooting much more stable and follow-up shots much quicker.
This stuff works. http://www.1911forum.com/ubb/Forum26/HTML/000684.html
It took Ayoob a matter of minutes to correct a few bad habits of mine and improve my speed shooting 100%.
Ok, I've written a book. Hope this helps.
[This message has been edited by Chris F (edited 05-18-2001).]