buy a complete engine. especially with newer engines, buying the parts separatly will cost you an arm and a leg and your left ear lobe. get it complete if you can. the only downside to using a lot of old electronic parts is who knows if they are any good. find someone who knows how to test them to make sure they are ok before you crank that sumbich up.
a guy you will want to become best friends with is Doug904, who knows the SOHC really well. And N3ELZ who knows the electronics. rwenzing knows his stuff too. Me personally, i know a lot about a little and a little about a lot, ill chime in if i do know