Note: the front sight milling on my DSP is different; all details are posted here.
Most DSPs have a longitudinally milled front sight dovetail, similar
to this: Amazon.com: HiViz Fiber Optic Front Pistol Sight (Red): Sports & Outdoors
Don't blame me if you buy that sight and it doesn't fit!
This was the rear sight I bought: Amazon.com: HiViz Taurus 1911 Fiber Optic Rear Sight (Green): Sports & Outdoors
I took a triangular metal file and removed metal from the rear sight, slowly, until I could get it to fit; it won't fit out of the box.
That's it. That's all the info I've got. Get thee a metal file and make whatever you've got work!