Since I have a PS2, I use something like this adapter to connect my controllers. I just wanted to let you know about that in case you wanted to try that solution, since it works great for me.

Other than that, I agree with /u/tydaguy. The Logitech F310 is cheap, reliable, and a dualshock clone. In your situation, it's what I would buy.

I have this one and can confirm it works. You just need to enable the "axis fix" option in Stepmania.

https://www.amazon.com/Trenro-Dual-PlayStation-Controller-Adapter-2/dp/B000F6BGXY

It should work fine for N64 games and will work decently for Wii games as long as you stick to games that don't use the motion controls very heavily. For Wii, it's far better to just get a Wiimote and a bluetooth adapter (if your computer doesn't have one already).

It seems the main advantage of the RZG322 is that it only takes up one USB port, which might be useful if you plan on gaming on a laptop or other computer with limited USB ports (and don't feel like using a USB hub). Otherwise it's basically the same thing. You should be able to use two RZG320s without issue.

If you're looking to use PS2-style controllers on your PC I'd recommend against getting the knockoffs and instead get something like this to use with some real PS2 controllers. I've never heard of these Cliptec gamepads so I can't speak to the quality, but in general knockoffs don't control as well as the real thing.