Lake,
The .243 is a great deer caliber! With a 100gr Remington load you get more than enough KO power to drop a deer out to 300 yards, and the point blank range is about 250 yards (that's the distance you can shoot at a deer-sized target and not have to hold over). In other words, it's plenty powerful and flat shooting!
As for the NEF rifles, you'd be hard pressed to find a better value, especially for a south paw

. They're simple, safe, decent-looking and well-made, not to mention quite accurate out of the box! I've heard of a few NEF .243s that were a little finicky about bullet weight, so you might have to try a couple different weights to see which is more accurate. I'd start with the 100gr, and if it doesn't shoot well for you go down to 80gr, but I wouldn't go any lighter for deer. Both of those will do you proud though!
You can get an NEF in .243 with iron sights, but if you want to scope it they come from the factory with the scope rail already installed (either way they're about $200). All you have to do is get a scope and rings and you're in business.
They're just the ticket for young shooters. If your length of pull (measure from the crook of your elbow to the inside of the 1st knuckle on your trigger finger for a rough measure) is shorter than 14-1/4", then you'll need a youth model, which has a LOP of 11-3/4". No worries though - when you outgrow the youth stock you can order a new full-size stock from NEF for about $35. There's just one bolt holding it on, and that's all you'll have to change. This way it will be a gun you can shoot forever if you want, or pass it down to your kid when (s)he is ready