If it's going on an OS, you can check into what options are availlable for it by calling Towers' 800 number; they should be able to tell you what is an exact bolt-on.
I agree with jones. If you use the pull starter right then it won't break. Only pull it out 3 or 4 pops at a time, generally about 8 inches max, and use quick pulls. It's not a lawn mower, remember it's got a plastic spool and a thin string and recoil spring, not metal and a rope.
Your problem might be your engine is out of tune so it is very hard to start. A properly tuned and primed engine should start in 3 or 4 short pulls when it's cold. Plus, they won't stall as much, which requires you to use the starter even less. If it helps you can use the trim to open the carb a bit. I don't use the trim and mine fire right up every time.
After break in you need to lean out the engine, because break in settings are generally pretty rich and put alot of stress on the engine and pull starter. You'd be surprised how many problems can stem from a tuning issue.
There are many tuning articles floating around the forum. Use the search button and you should find what you need pretty quickly.
I suppose I get a little overzealous, but it does usually start pretty easily (if the pullstarter stays together)
I still would like a non-pullstart option, I looked on towers website and they have a tiger drive that claims it will fit the .15 cv-x, but tiger drives website seems to claim differently. I was hoping someone had some experience seeing that it is a somewhat common engine.