NICE!
Congratulations on your first Shotgun, the first one is always special, and with Mossberg, my opinion is you really cannot go wrong.
I have the 500 (3" Mag) which I bought a Mossberg 24" long Rifled Barrel (also 3" Magnum) that is Ported and came with Williams Tru Glo sights (green in back, front red). The rifled barrel is just blued shinier than the rest of the gun. I could care less.
I got that barrel straight from Mossberg during the gun crunch two years ago (about $180 or so sounds right).
I bought a couple hundred dollars worth of all different types of slugs to test the barrel and after shooting an 8" diameter stump at about 30 yards and hitting it every time (offhand), I decided there was no reason to burn up all my slugs!
May you have the best of luck and the best of fun with that gun!