Your options should be much more broad than Pinnicale and a 135 air ambulance gig. With that sort of time there should be lots of options available to you on both the 135 and 121 ends of this industry.

Do what fits you best. The more I think about it, the more I sway to the 135 side. The idea of not dealing with security, flying to many different airports and knowing your passengers appeals to me.