Gloss Black Acrylic

You are going to spray some metallic over the gloss black?

You only need the gloss black base for high shine colors like Stainless Steel or Polished Aluminum, etc.  Otherwise having a gloss black base won't make any difference.

Alclad II's Gloss Black Base works very well.  It has a bad reputation because of a bad batch that was sent out about 5 years ago.  But that problem was corrected almost immediately.  

I have also used Mr. Color Gloss Black, which is a solvent based acrylic paint that is really nice.

I have seen guys use Tamiya Gloss Black with good results as well.  

I used to use Testors Gloss Black enamel for undercoating before Alclad.  But I ran into problems recently with the Alclad (lacquer) disturbing the enamel undercoat, and will no longer go that way.  I tried the Alclad lacquer black primer and it is working well.