Comp.
Gunny: Look around as suggested. The type of competition that you decide on will influence the firearms that you need. Or....the firearms that you have may influence the competitions that you enter.
For a 2700 Bullseye (also called "conventional pistol") match, you'd need two guns at least, a .22 and a .45. There are three 90 shot sub-matches in the 2700 - a .22 match, a centerfire match, a .45 match. Many shooters use the .45 for both of the latter matches.
Pete