Suck gate is a generic term to any wake shaper that mounts to the side of your boat with suction cups.

I had a homemade (single) one on my Supra - probably $30-40 in materials. Worked great.
Companies also make them for $200 and $300 for a brand name manufactured one.

There are companies that make single ones and double ones (Surf Mode) or stacking them like NautiCurl.
Some make a bigger face - like the Liquid Force Edge Mega Wake Shaper

What is the best? Opinions will vary. To me, the best one is the one that stays on your boat. Ones that float are a plus too. If you had Brand X and Brand Y mounted in the same hull location and mounted in the correct water position, I doubt you will see much difference in the wave. Can't really listen to the manufacturers b/c they will show bias photos of how theirs is the best.