All of the Ruger revolvers you list are excellent choices. Here is my input...
.44 Magnum versus .45 Colt: .44 Magnum wins in my book because unless you have strong emotional ties to the .45 Colt, the .44 Special is the ballistic twin and will fire in a .44 Magnum revolver. Beyond that, the .44 Magnum will handle everything from self defense to stopping large game with off the shelf ammunition.
If you are going primarily for cowboy shooting (the inclusion of the double action Redhawks suggests that you are not), I would opt for the Vaquero.
For any other purpose I would opt for the standard Redhawk as it gives you the most versatility to perform tasks such as hunting, self defense, plinking, bowling pin, etc. It is also lighter than the Super Redhawk which is optimized for handgun hunting.
If self defense is not a concern and you prefer single action revolvers, then either of the Blackhawks would be fine choices.
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- Anthony (the crazy Italian with a .41 Magnum)
"Civilized people are taught by logic, barbarians by necessity, communities by tradition, and the lesson is inculcated even in wild beasts by nature itself. They learn that they have to defend their own bodies and persons and lives from violence of any and every kind by all the means within their power."
- Marcus Tullius Cicero