Re: Completely New to This
AFP - tough choice between 4 and 2 stroke. 4 strokes will generally be more reliable than a 2 stroke, but there are MANY 2 strokes around here with thousands of miles on them.
If you go 2 stroke, I would suggest taking your time and tearing the engine down before installing. Lots of little cleanup items from shoddy chinese QA that will improve reliability. Things like bad casting seams that need to be ground/sanded off, sand the head surface and other mating surfaces to be smooth and flat. Also spend lots of time getting the rear wheel drive sprocket true and perfectly lined up with the motor drive sprocket. I'd also get better hardware before buttoning it up.
Personally I love 2 stroke motors and have an extremely reliable bike running an el' cheap'o Chinese kit.