Mostly range shooting with possibility of shooting critters.

YES!

Lol just an update I currently own a marlin 917V. Other than the weight between the American and varmint will I really notice an accuracy difference?

No clue about the American,  but I have a varmint, and I freaking love that gun.

One of my favorites

Just ordered it.

which one did you get?

I have a Varmint and fell in love right away.  It shoots bug holes out to 100 and is a pleasure to shoot.

Define "bug holes".

I have both a CZ 453 Varmint and a CZ 453 American.

Both will shoot the occasional 1/2 MOA 5 shot group at 100 yards, however the American averages 1 MOA with match ammunition and the Varmint averages around 1.25 MOA.  

The Varmint has a lot more variation than the American.  However, they are both well within the normal range of accuracy for CZ 452s, 453s and 455s.

CZ went with a slightly shorter, straight tapered barrel on the CZ 455 Varmint, compared to the 452 and 453, but the overall weight is the same.

The major difference in choosing one over the other comes down to style preferences, as the .22 LR doesn't generate enough heat to make the heaver varmint barrel profile a factor.

I envy you.  I'd love to have a 453 as I am in love with CZ's set trigger.  I have the ST on my 527 Varmint.

To OP, I'd get the Varmint, Super Match, Ultra Match, or Ultra Lux.

I picked up a 452 American a few years back.  They are nice rifles.  

I still need to get a scope for it. 

I picked up a 452 American with a threaded barrel a few years back.  I really like that gun, especially when shooting it suppressed.  It is really quiet and decently accurate for a 22.

With the 452, you can pick the configuration you like based on personal preference. I have an older 452 and a new 452 Scout. I have shot them side by side to compare, and the accuracy is identical. They both seem to like SK Standard Speed just fine. I don’t think a heavier barrel would improve accuracy, but it may be just what you want for your own reasons. Go for it.