I did not use Chromo Base, I used Paint Shop System from Dupli-Color, it is available at Advance Auto Parts or it can ordered from Summit, Jegs, etc. About $20 per quart.
http://www.duplicolor.com/products/psFinishSystem/
You could use the spray bomb style bedliner, I had a kit sitting on the shelf left over from doing my truck bed, it came with the undercoating style application gun. I used Raptor.