$1500 budget ought to get him about any mass marketed hunting rifle he wants and a pretty good scope to boot. Me, I would be picking up a Tikka t3. I would then walk across the floor and get a pair of Warne low rings. All this would be topped with a Leupold VX3 3.5x10x40. With the rest of the cash I'd buy ammo and shoot this rascal till it behaved for me. This is exactly what I did six years ago, (VXII 3x9x50 $900 budget) a drop to 40mm is the only change I'd make I suppose.
The SIG is about market price, you weren't robbed anyway. Were it me I'd feed it about 250 rounds of Winchester white box ammo. Then about as many Speer Gold Dots as I could afford to verify function. Substitute whatever high quality HD round you are comfortable with.
If you are a new SIG shooter please be sure to clean both the gun and mags (disassemble both) to remove all the preservative. It can be gummy if any is left behind. Grease the rails with a quality grease, at the range don't be afraid to take it down and add a bit of oil to the rails once in a while. Steel is harder than Aluminum and can really abuse the frame early on until things seat in. I'd keep it damp at the range, in a holster a thin film is fine so as to not attract dust and lint.