Which resin?

Before I get flamed, I did try searching on choosing the right resin.  I have already done some upfront research, but I guess my main question is, do I have to buy both types of resin - layering & surfacing, or can I just stick with surfacing?

From my understanding, layering stays a little tacky, that allows you to add more layers after the first several are already "dry".  Whereas surfacing resin leaves a waxy finish.

So basically, if I put down all my layers at once, do I really need the layering resin?

Thanks in advance.

The wax comes to the surface during the curing process to keep out oxygen. To get rid of the wax just use some accitone (not sure on spelling) on a rag before you start to sand. You can put 2-3 layers on at a time but that’s it due to heat build up. Then before priming use a wax and grease remover. I use Bondo 404 it works great.