Taurus M62: Rifle or Carbine?

I'd go for the carbine myself. Look at Dick Metcalf's chart in the review he wrote up...
http://www.galleryofguns.com/shootingtimes/Articles/DisplayArticles.asp?ID=269
The difference in accuracy (at 25 yds.) was 2/100's of an inch. From .65" for the carbine to .63" for the longer barrel.
YMMV but it still looks like a very FUN little JMB designed firearm at a great price

I bought the rifle because I found it more aesthetically pleasing. The longer barrel balances the visually long, thin stock.

The short barrel is adequate to take full advantage of the .22 LR -- you don't get much more velocity from a longer barrel.

On the other hand, if you're going to use iron sights (especially the tang sight Taurus makes for this rifle) the longer barrel will give you a longer sight radius. And the extra weight hanging out there will make the rifle easier to shoot well from the off-hand position.

As a dedicated squirrel hunter, I'd say the tip goes to the longer barrel.

Carbine. And get the youth model that comes with two different length buttstocks. That's what I did, and I love it.

The carbine makes a lot more sense to me than the rifle. It is lighter and handier, and plenty accurate. The M62 is the ultimate plinking gun. You don't want a lot of extra weight or length getting in the way.

It's also a great rifle for new shooters. It's light, easy to handle, unintimidating and FUN! That's why I recommend the youth model. With the short buttstock on it, it's great for training kids. And, it's a steal at about $225 (when I bought mine a year ago, anyway).