Vega, center or rim fire simply refers to the type of cartridge that is used. The rim fire has no real primer which is incorporated in the cartridge case itself. It is "ignited" by the firing pin striking the "rim" of the cartridge. The only modern example of rim fires, which are limited in their inherent power, is the .22 in either short, long or long rifle. In times past there were several rim fire calibers including the .41 and .32 to name two.
Center fire cartridges are ignited by the firing pin striking a primer located in the center of the case. These primers, with a few exceptions, may be removed once fired (spent) and replaced for reloading. Center fire cartridges by design can be and are more powerful.
I'll let someone else field the question as to which you should choose and only say your choices are many and largely a matter of personal taste.
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Gunslinger
We live in a time in which attitudes and deeds once respected as courageous and honorable are now scorned as being antiquated and subversive.