i'm building a light weight a3 ar and I was wondering if I should go
with a 16" m4 contour are a 16" light weight??? I am geting the
kit from del-ton so i can get a dpms light weight or a wilson m4.
and is WILSON better quality then DPMS??

I'll use YHM light weight forearm and a ACE light weight stock
on my new build.

any ideas on how to lose more weight????

I don't know why you are asking about a Bushy lightweight barrel in the title and a DPMS lightweight in the body, but if the Bushy is an option, I would say, yes, get it, you will like it. Cannot attest to the quality of the DPMS barrel. Don't know what your intended role for this weapon is, but that will have some bearing on barrel selection. If you are just trying to save weight, the lightweight barrel is the way to go...but I guess that is pretty obvious...