Replacement guide for different cleats?

Wellgo make a variety of aftermarket replacement cleats and pedals for various systems, including Shimano's SPD and Look Keo. They should be (almost) completely compatible with the equivalent system's branded cleats. I've personally used Wellgo Keo-compatible cleats as a replacement for Look-branded cleats, and there were no issues at all.

Assuming you're talking about these Wellgo 6-degree cleats then the Keo equivalent 9-degree float should be a drop-in replacement.

The way I change cleats is to take a Sharpie and trace around the base (the heel-facing end) of the old cleat before removing it, and then align the new cleat to that line when installing the new ones. It shouldn't require a fitter, since the plastic is as identically shaped as they can make it.

(Just to be clear, trace along where the cleat meets the shoe, as indicated in this picture. This shape is dictated by the shape of the pedal, and any compatible cleat must have this exact shape here.)