It depends if you care about noise and cost. It also depends on how much you can spend.
In general I would rather buy a 25 cal air gun.
If I was just sitting on a bench punching paper at 100 yards (which is essentially plinking), I would probably want more shots per fill as I would go through a lot of air. Less expensive ammo wouldn't hurt either.
I find my 25's to be more than capable of grouping at 100 yards. The weight of some of the heavier 25 cal ammo is not that different from most 30 cal pellets.
Then again, I care (a lot) about noise and I hate having to fill my guns with air too often. People get great results at 100 yards with an FX boss, a 30 Bobcat or RAW 30 etc.