I think so.  While a match barrel will usually be more accurate with FMJ than a standard barrel, it still won't be anywhere near "match accurate".  For that, you need good (and much more expensive) match ammo.  It sounds like you've honestly evaluated your needs and ammo-buying practices, and have correctly chosen a standard barrel.

Lots of folks buy match barrels, but after a box or two of match ammo to prove to themselves how accurate it is, try to feed it standard military FMJ, and often get poor reliablity due to the tighter match-spec dimensions.  I try to explain that match barrels should be feed higher-end ammo, but most folks don't want to hear it.

-Troy

Especially if you are going to shoot a lot of surplus ammo, a barrel with a 5.56 chamber will be better for you than one with a .223 match chamber.  Based on what you are saying, I would not get a match barrel, even at the same price.  I would suggest you have your smith open the gas port a little, but if you have the opportunity, have it cut first and shoot it. Then have it opened up if you need to.

We use slightly larger gas ports on 18" barrels and occasionally use adjustable gas blocks to regulate it.