... strange, I just joined two or three days ago, got a bunch of answers for a bunch of questions, sorry you got snubbed
I've never paid for new sights, installed new ones, .. heck the 1911 I've got now is gi so it doesn't even have a slide cut. I used to have a taurus pt1911, it wasn't a great pistol but the thing shot pretty accurately - it had heinie sights.
then again I wanted gi so I won't get snags on my torso, thigh, etcetera... I just decided to concentrate harder
single shots should be achieveable but rapid fire in a defense situation.. I can't personally track the sights in rapid fire either way but my eyes are bad. I forget the brand name but some company makes triangle/pyramid sights- maybe you can look that up and get a few reviews on that one (it seems like it would work but then again I was thinking ccw with mine so I'm no help)