So just for fun, I pulled up a P250 Drawing.
I'm going to change my answer to "no". A P250 doesn't have a sear, The hammer drops off the trigger bar directly at the end of the trigger stroke. It also doesn't have a disconector (Probably because the hammer follows the slide and there's a firing pin safety.)
So you'd need a completely redesigned hammer, A single action sear, some way to fit that sear into the frame, probably a disconnect of some kind, depending on how that safety lever actually works. (Sig does it in their trigger bar/reset in the factory SA/DA models,but I can't tell from the drawing if the 250 is set up that way) Probably a custom trigger bar. Heaven help you if you want to scab some kind of decocker in there. I'm honestly not sure there's enough room without gutting the frame and starting over. But it ain't going to happen.
I would suggest looking for a classic P series.