Colombian boas are nice. Males usually top out at 6 ft. There's a lot of really nice "normals" that are not too expensive as babies that have beautiful colors. They usually have great temperments (there's idividual exceptions though), and are easy to care for. My colombian seems to be in different parts of his cage at different times of the day, and is very active when I take him out. Down side is that males need 4 ft cages (females need even bigger).
You might want to look into ball pythons and hogg island boas if a colombian's caging is out of your space limits.
There's also large snakes in the colubrid family, but I figured since you mentioned the blood python, that you were interested in boids.
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1.0 sinaloan milksnake
1.0 western hognose
1.0 colombian boa