Timing Chain vs. Gears vs. ?Roller

I am getting close to putting my 77 440 (RV) together, I thought it would be a good idea to replace the timing chain,water pump and freeze plugs before install.I was ordering my gasket set when the question came up regarding thereplacement of my timing chain.

My question is, would gears be better vs a chain? And what exactly is a roller motor, double roller chain?

Iwould rather do the best thing for my street/strip motor now as I am not mechanically inclined and doing this all again soon scares the #$%^ out of me,especially, when the 440 is in my Dart. Thanks