I would ask ..what are you intending to use it for ? General use , hiking , trapping , hunting ....probably the 5.5 but if its gonna be pretty much hunting only....I'd opt for the 7.5. Sounds like its already ordered , I was gonna suggest the Redhawk. Its a fine handgun , can be had in various configurations. and its as strong as a tank !
OMHO , regards , irold