If you use stain unless you use a sealer it will stain from those elements you described. The epoxy (if you get the right one) will be easier to keep clean. Make sure you get one that doesn't peel or stick ti tires.

Epoxy is definately more durable. Must not drive on it for about a week. Prep work is everything for your final product.

Hello bvanlier,

You'll benefit by doing a little homework first.

Epoxies are a form of sealer. They can be opaque, translucent, or clear. Common garage floor systems will encapsulate vinyl flakes or ground quartz in an epoxy or poly aspartic.

Stains are not sealers (though there are pigmented sealers sometimes sold as "stains"). A stain just provides color. Stains can be applied in a number of ways to achieve a wide variety of effects.

Stains will need to be sealed.

Epoxies can scratch relatively easily. They are most often top coated with another sealer, like a polyurethane. Polyaspartics are an alternative that are sometimes used instead of the epoxy/urethane route. All coatings can scratch.
These products do not breathe at all. If you have moisture vapor tranmission (MVT) you must use a moisture blocking epoxy as a primer first. MVT testing is easy but vital. If you have MVT and no blocker, your floor will delaminate.
Both of these options should have the surface profiled by diamond grinding to open up the surface and provide a good mechanical bond.

Stains come in many forms from acid stains, to dyes, to stains. Dyes and stains are availble in water or solvent bases. There are too many sealer options to list.

For the conditions your floors will have to endure consider concrete grinding and polishing.
You can still stain your floors. You can control how much of a grind you get. You can barely profile the cream or expose the large aggregate. Densifiers are used during the process to close off the pores of the concrete making it more resistent to moisture penetration and stains. The right penetrating sealer would finish this, giving you stain protection from the really nasty acidic and alkaline stuff.
You can have the finish glossy like a mirror, but that gets slippery when wet. You could stop as low as 200 grit and have a beautiful floor! I wouldn't go over 800 to avoid slipping.

To do this right find a professional in your area that is familiar with products like Trinic LLC and Lythic Solutions. Prepping, staining, and sealing properly take training and experience.

Hope that helps,
Vincent Cathcart
VC Studio Inc.
vince@vcstudioinc.com