I'd also go with the OS, if you don't mind the extra $$, or the 3.3 as the cheaper option. The Dynamite is a decent engine but is known for having a somewhat short bearing life, plus it's been discontinued so you may have a harder time if you ever need parts. A Traxxas starter will bolt up to...
I had the .19 for a while, but the main bearing went out last time and took the piston out with it. Until then though, it was a great cheap engine, it held a great tune and would idle all day. Power wise, I think it had slightly less torque than a 3.3 but was still plenty for general bashing...