For me, the choice would be a no brainer if choosing between the two caliber wise. Both are built on the 'large' frame....
Since you don't reload (.45 Colt is a reloaders cartridge), the .44 original Vaquero may be the ticket shooting either .44Spec or .44Mag. The only downside is it is a fixed sight, so realize the limitation there, On the other hand they don't make it anymore either and you would have a 'cowboy' gun
. Everyone needs at least one fixed sight revolver....
Really it comes down to what 'you' want. Buy both if it really a hard decision
.