For hardware encoders, you might want to look into options like the Elgato Game Capture HD60 S or the AVerMedia Live Gamer Portable 2 Plus.
Those are not encoders. Those are capture devices. NOT the same thing.
Encoders take a final, finished, mastered result as a series of full-detail frames and audio, and compress it to send to a final destination like YouTube, Facebook, Twitch, a recording file, etc. They're on the output end of the chain.
Capture devices, like you listed, are on the input end. Again, not the same thing. You might be accurate in their compatibility, but not for their purpose. Or, you simply have the terminology a bit off.
Capture devices are relatively easy to change and swap out, if you're okay with USB. (generally works for one HD video source per internal USB *controller*, NOT per external port, because an internal hub is no different from an external one...)
Encoders are (almost) always internal to the machine (*), so you're almost stuck with what you've got. You might be able to change a graphics card (GPU) to get a different hardware encoder, or to get one at all - and the same goes for some processors (CPU's) that have that much graphics on-chip - but it's always that involved.
(*) There *are* standalone hardware encoders that take their own power, their own network connection, and a standard physical A/V signal, and stream that A/V signal all by themselves. But the people who use them with OBS often have trouble getting everything to it like they want, because OBS is not meant to produce an external signal of its final result. I really wish it did; it would make a couple of *my* rigs a lot easier too!