There is no question as to which has more energy, the 185gr +P will not only possess more energy (due to increased velocity) but it will also dump most of it, all of it infact if there is no over-penetration.
According to Marshal and Sanow, the 230gr Federal HydraShok is tops, with Remington's 230gr Golden Saber coming in (very) close second.
With any full 230gr weight JHP, penetration will certainly not be a concern, you will always experience ample. I cannot say for sure what to expect penetration-wise from a 185gr .45 caliber slug at +P velocities. There will surely be more tissue disruption, but as for penetration, who can say... expansion dictates that. Because a round is marked +P does not guarantee deeper penetration. Increased velocities sometimes equate to more pronounced and rapid expansion with JHPs in general, and this usually is counter-productive to penetration.
Either round you describe will serve it's purpose, and I seriously doubt either will fail if you uphold your end of the deal.
Personally, I have 230gr Federal HydraShoks in my Kimber Custom Classic (home defense) and Hornady 200gr +Ps in my Colt Commander for my Jeep.
Good luck.