My preference is the valve that both OMS and Halcyon used to sell. OMS called it the Sweet Pee valve, but unfortunately I don't think it's made any longer.
It had an inner and outer piece like all the other pee valves, but it also had a separate cap over the mushroom valve on the outside. That meant you could use the inner and outer sections to seal to the suit, and the use the cap to capture the outer bullet, or tech skin material.
The good news is that the current Dive Rite valve is built the same way, with a cover over the mushroom valve that screws off the outer half of the valve, and enough of a flange to capture the outer skin material effectively.
It's a good choice for a Fusion.
Either way, I've found it works best if you permanently glue rubber gaskets on the inside and outside of the suit to allow the valve to seal against the gaskets and yet still be removable. If you valve doesn't come with rubber gaskets, you can usually find suitable gaskets at the local hardware store, or cut the gaskets out of an inner tube and secure them to the suit with either a silicone adhesive, a suitable seal cement or with Aqua Seal. Even though Whites isn't real hot on Aqua Seal, I've never had any compatibility issues with it on my Fusion.
I never saw a need to reinforce the inner bladder fabric with a patch (and mine has held up great for 8 years now) but it does help to reinforce the area where the valve will poke through on the tech skin with a circular patch of Iron Mend wetsuit repair material. It adds some thickness and prevents the material from stretching or fraying. You do however also want to cut the hole in the skin undersized so it stretches a bit over the valve to help it stay put and not get pulled out from under the outer cover.
Otherwise, I'm in agreement with the linked thread on installing a pee valve in a Fusion.
