Omni will not cover as well l and you will use significantly more base coat to get good coverage. I use PPG and have painted with Omni. It's usually on something that will be sold quickly, You can get good results with it but it doesn't hold up to the elements very well.

I like Deltron DBC. It is easy to match if you need to make a repair later and covers well. I like the PPG 4000 clear. It lays down nice and polishes out well. As with most things, you will find opinions all over the place. There are other paints that will work well. I have always used PPG so thats what I am comfortable with. Like others have said, the paint is only a small part of the refinishing job.

You can buy the worlds most expensive paint and If your bodywork and prep are poor it will look like crap.