H1 or OPT

I am in OPT at US. I can also apply for H1 right now. I will probably get my Canadian immigration approval before the expiration of OPT. But i am planning to just land Canada and then come back to US.

So 1) is that still right that I can come back to US within 30 days without any trouble after landing Canada?
2) if 1) is right, which one i should have, OPT or H1 ??

Thanks!