Another optic to consider would be the Holosun EPS. Per Holosun, the non-carry standard EPS has a 0.63"x0.91" window size which is identical to the window size listed for the 507C. The EPS has a 507k footprint.
I recently switched my 507k for an EPS on my CZ Sp01. The optic does hang over the slide a bit but does not add to the maximum overall width of the gun since the stock slide stop is wider the optic overhang. The co-witness is about a lower-1/4, which is highly usable.
See photos below: In the down the sights photo, I would say it appears slightly wider than it actually is.
SP01 w/ 507k, down sights:
SP01 w/ EPS Green MRS, down sights:
SP01 w/ EPS Green MRS - profile: