Rust oleum makes a product that would require the surface grinding mentioned above.
Due to government tosha regulations melted aluminum pots that are transported have to have a smoothness of (whatever the specification is).
They grind it flat, then sand blast it after it is flat enough. Then they use a power trowel and the rust oleum epoxy on the floor. Let it cure a few days, and the only thing that will make it look bad is a pot of spilled metal.
If you are already flat, with a broomed surface I would think you would be rough enough to spread. It looks great in grey, not too slick. And the abuse it takes here in a month you couldn't do in a lifetime. Looks kind of like a grey painted floor, but the color is the mixed in ( sand) I'm not sure it is really sand. And if it gets a chip, the color is all the way thru. It also is chemical resistant, so if you spill something it wipes right up.
If you have a place near you that rents a power trowel, I think the product ships in a 5 gallon pail. So I would think you could have it shipped to the house.
I asked the contractor applying it how much it would cost for a garage, he quoted me 400 for a 3 bay size. But that was only if he could come right after the plant job. And that's been 12 or so years ago. I've seen other products that claim to do the same thing. So materials might not be that high.
William. Good luck!