I am going into the paint booth next week for a gallon of epoxy and a gallon of surfacer. It will not get worked on this winter, but will get driven daily in the rain. Am I better to leave it in the surfacer or buy a gallon of that cheap junk on ebay just to have a top coat on it until March or so?

I sptayed my front clip with 2 coats of epoxy, and no surfacer.

I figured when I was ready to paint, I would reblock it, shoot another coat then some surfacer when it's ready for paint. That was 4 years ago.

Go with the good epoxy.

I just worry about UV penetration and moisture getting under the primer. Remeber, I'm in CA. Even during winter we still get a pretty fair amount of sunshine.

I was told that good epoxy will hold up in about any condition, but you will have to reblock and shoot a new coat.

I used a metal etch in spots where there was bare metal.

Besides, the "rat rod" movement has been using this method for a long time.

The rat rod guys are using flattening agents in the top coat system.

Are you going to use a catalyzed surfacer? If so you would probably be ok doing it like that. If you are just using a plain old acrylic surfacer you would be better off just using the epoxy and leave it at that. Those older acrylic surfacers still have a tendency to draw moisture.

I should have been clear on that, I am using the Nason line. 421-18 2K select primer/surfacer and 491-35 Ful-Poxy epoxy/sealer.

Now, apply the epoxy and 2K and leave it at that, or buy some cheap top coat (I found a gallon with activator for 50.00 online) to keep it sealed through winter?

i wouldnt go with cheap top coat leave it in epoxy if you feel better putting some color on it go with something good so you dont have to worry about getting it all off .

Just spray 2 good coats of epoxy and leave it be.
Epoxy is a good sealant against the elements. The only thing you will see is that if your epoxy is black it will start to chaulk up or turn whitish. When time comes to apply your 2K primer surfacer and paint just sand the epoxy apply 1 of epoxy coat and then apply your surfacer or paint.