We actually have competition contours in several different configurations. The one I did for Zak was a Krieger. He was planning to shoot it in the IRTC, which stresses a barrel a lot more than any "regular" three gun match would. Krieger stainless is a bit more resistant to throat erosion than most, so they handle the extra heat better.
The configuration that Wes listed above sells for $1350 with shipping (CONUS). Adding a lightweight competition carrier adds $60. Forward assist works correctly too. The Forend that PRI does for us uses an alloy barrel nut and a different hole pattern in the carbon fiber.
We do flute some of our competition barrels. Other than special orders, we are only doing our premium Lilja tubes with flutes on a regular basis. The flutes are primarily cosmetic but they really make a visual statement. The combination of the Lilja blank and the fluting adds about $200 to the cost of any configuration. We are fluting 17" barrels with 12" gas systems (rifle-length) and 16" barrels with 9" gas systems (mid-length). We have not fluted stock competition barrels in 18", so that would be a special order barrel. Over 95% of the competition barrels we do are 16" and 17". With three-gun matches ending at around 400 yards, many far less than that, extra barrel is not needed. Plus, the shorter guns are a lot easier to manuever in tight corridors, in and out of ports, etc.
Fluting carriers is certainly doable. There is a fair amount material that can be removed, about 2.5 ounces from a full-weight M16 carrier. Far more important than lightening the gun by two ounces though is what that weight reduction can do for your shooting. By eliminationg nearly 20% of the reciprocating mass it is possible to reduce felt recoil significantly. While .223 recoil is not abusive, it can certainly move sights off the target in a big way. And it happens twice on each shot, once when the carrier goes back and again when it comes forward. By regulating the gas going into the gas tube and correctly springing the recoil buffer most gun movement can be eliminated, even on a very light gun. Once that happens it no longer makes sense to have a longer, heavier gun to "be more stable" for longer shots. Whether offhand or supported, a lighter gun is often easier to steady than a heavier one, especially at the end of a long stage lugging the gun along.
While I would not recommend these for "across the course" use, they are certainly capable of performing well on difficult longish shots. Beyond 400 yards or so I still like longer barrels. Prone at 600 the extra velocity makes for better groups, no question. But they aren't that much better, and there are no 5-600 yard shots in any 3-gun matches anyway. 90% or more are under 100 yards as a rule. Faster is better, as long as you still have accuracy available on demand.
On several occasions I have loaned a 17" gun to a highpower shooter to try out. One of them ended up winning an egg shoot with it, his first ever egg win to boot! I figure if anyone can hit an egg at 600 yards they are doing well, and if they can do it with my gun, well...