eeb,
You're asking a bit of a difficult question to answer, since 'generic' 2 part epoxies come in all brands and strengths. I recommend you look at some of the manufacturer's sites for technical specs. Since Brownells doesn't really make much if anything, and certainly not epoxies, they are simply repackaging and selling another major maker's product.
Also, Aircraft Spruce & Specialties in Norco, CA and Peachtree, GA have many things a person might need for gunwork.
http://www.aircraftspruce.com/ For a thin, high strength epoxy, I'd use one of the laminating resins from Aircraft Spruce. Give them a call and discuss what you're doing.
http://www.devcon.com/http://www.loctiteproducts.com/products/