Here's a post with suitable plugs. I would stay with something from this list. Forget about those generic plugs on amazon.
http://motorbicycling.com/showthread.php?t=10560
You can probably find this in a thread here but I would say that you only have to worry about a long plug hitting the piston. Again, stick to the list and you should be just fine.
NGK - B6HS, B7HS, BP6HS, BP7HS seem to be to be the most popular
I don't know if the pull start would help and you may have fitment issues with the pedal clearance. I don't know as I've never used one. The forum is your resource and you'll probably find some good info if you comb the threads. Experts may weigh in here with advice.
For your first start up I would leave it and stick with the bump start so you can peddle for a while if that's what it takes to fire it up.