It all depends on the match. If they are running 3-gun in pistol bays, then any of the above will work, Mini-14, SKS, AK, pistol caliber carbine (including M1 carbine). Yes, ballistically, M1 carbine is a pistol caliber.
The more the distances go out, the less you want any of these. The pistol caliber bullets will require too much elevation and hitting targets at 100+ yards is about impossible. And, yes, you can hit targets quickly with an AK, but an AR in equally-skilled hands will beat you. Reloading an SKS after the stock 10 rounds will get old fast, so you will want to change out the fixed 10-round for something with higher capacity. If you are buying new, the AR or higher price range will be the way to go.