Since you are going to end up with both eventually, buy whichever one you can get the best deal on now.
Or whichever one you have more ammo for now.
I'd skip the Beretta and go for a sig P226/9. You can swap the upper of the sig and go .22LR, 9mm, .40 and 357 sig. Awesome gun.
The .22LR upper is what I shoot most of the day at the range. Then I finish up with a few hundred rounds of 9mm. The sig is one of the last handguns I bought and by far my favorite.