Hey, Onmi is a fine paint. You just have to define what end result you want or need. My flatbed trailer and the front loader will be fine with Omni - single stage, most likely. On the other hand, it is pretty unlikely that my '56 Studie will ever see any. I freely admit to even using Rayflex off eBay on my motorhome but it needed to be painted NOW and will still see quite a bit of body work. Down the road a bit, it will recieve better paint.
You just have to decide: is it a beater, a nice cruiser or will you be in those shows where you drive on the grass past an audience in tuxedos?
Match you paint to the job
That being said, the base coat/clear coat system is my default.