I added "nipples". But, otherwise, yes, correct.
This one question could warrant a book as an answer. I have three books on the shelf that recommend different approaches to achieving good wheels. One thing I'm going to be pedantic about is differentiating between "strength" and "durability". What you need is as much the later as the former.
Build quality. Really. It's that important. With regards to components, it largely comes down to, "how much would you like to spend?". Very popular amongst budget conscious clydes are the basic cup and cone Shimano hubs. There's not much wrong with them. They work and have a steel freehub body that is as durable as anything else out there. With regard to rims, you're looking for something that can support 130kgf of drive side spoke tension without starting to collapse or having the spoke nipples pull out. The easy answer to that requirement is any of several 30mm deep V profiled rims. Dt Swiss 585 and Velocity Deep Vs are popular. There are plenty of other options that can serve just as well. Brass spoke nipples, because they are more durable than aluminum alloy ones. And, some quality, name brand, stainless steel spokes. Wheelsmith, DT Swiss and Sapim are the three most common brands. It's debatable whether you want straight gauge (14ga./2.0mm) or double butted (14/15/14ga 2.0/1.8/2.0mm) spokes. Technically speaking the former are "stronger" but there are many, very experienced wheel builders who service the clyde market and home builders that will contend that the double butted option creates a more "durable" wheel.

But, even given all those things, the wheels will only be as good as the builder that performs the final truing, stress relieving and tension equalizing.



In many case they'll use the same "rim". But, they do use different "hubs". Dedicated single speed/fixed gear wheels use a hub that the cog or single cog freewheel screw directly onto and lock. Multi speed wheel hubs will either accept a "freewheel" or have a "freebody" onto which a "cassette" is attached. In some instances people will use a multispeed wheel for single speed by placing a single cog on the freehub with spacers either side to fill up the unused space.

Don't apologize for questions. You're trying to educate yourself. One of the best resources you could imagine for clyde wheel concerns is the "search function" for this very forum. There are dozens and dozens of threads within this subforum that address just about every imaginable question you could have at this stage.

Basically. You're current wheels aren't hopeless. They tick off several of the features you're looking for. What they may lack is name brand spokes and a quality build tensioning job.