I think it'd be sweet to see a carbine in .357sig especially if you've already got the ammo stores to keep it fed. Obviously the economy side is tempting, but you shouldn't let all that tax free money go to waste either! God bless and good luck with this decision. I used my deployment cash on a cruise where the all the sand was lined with water... It was "nice."
Im a big fan of the 45 acp but a 9mm carbine would be the most practical with 9mm poppin up everywhere.I havnt gave much consideration to the 357 sig (havnt seen too much of it until recently) just because of the availabilty & price.I really agree with some of the above posts that if you served you deserve all of the above.Be safe soldier & thanks for serving
Can't go wrong with any of your choices, all will be fun either way. 9mm will probably be the most economical though. Olympic Arms has a nice selection of 9mm, 10mm and 45acp. I really like the thought of a 10mm sbr, 10mm in a handgun isn't that much fun but in a rifle that would be some fun. Either way enjoy your new toy and show lots of pics.
Last but not least thank you for your service and stay safe.