I have an FNP-45 (DA/SA, safety) - I don't really like it. On paper it was great, I got a fantastic deal on it new back a few years ago, but it just isn't ergonomic (too large, ungainly for my hands). The DA/SA in conjunction with the safety I thought would be optimal, but I don't like it. Frankly, it's too complicated. The trigger is ok, has long pull. There are a considerable lack of accessories out there, and in conjunction with 45 ammo prices on Oahu, it now just gathers dust somewhere since I bought an M&P.
On the RDS side of things, I'm thinking of putting one on my M&P. There are people out there who will mill out the slide to accept a Trijicon RMR / Leupold Deltapoint / whatever, but given the fact that the mounts are not currently standardized, you need to know what you will mount before having a slide shipped away to be milled.
Of course, if you buy an FNP-45 tactical model with the slide already cut, then you can just remove the plate and mount an RMR or whatever you want. It comes with two mounting plates so you can avoid the whole "which optic do I buy?" because there are two styles.
But yes, the FNP-45 tactical has a safety and decocker. I think if I were to do it all over again, I would have gone with an M&P 45.