To sum it up. Research both species for their needs and see which one you can meet better. Also it comes down to which one YOU like more. I mean personally, I really dont care for blood pythons. They just look like a oversized less morph version of a BP. Now if you listened to me, you would have a boa but again, that is MY opinion.

The only person who can answer your question is you really since it will be your snake for years to come.