I just did the floor in my 28x32 detached before I moved in.
I spent 2 days grinding the previous owners Home Depot kit off.
I ordered a "job on a pallet" from Armorpoxy, it cost about $1300 if I remember correctly. The only thing I would suggest is to get some extra top coat(clear)
The kit included:
Acid etch
Primer
Epoxy
Fleck (decorative flake)
Top coat (clear)
Antislip (essentially sand goes in the topcoat)
18" Rollers
Roller handle
Mixing buckets
Boxing
Mixer (need your own drill)
The company was awesome to deal with, and super quick on delivery
https://armorpoxy.com
I have a thread in the ManCaves column with some pics of the job.