Are you looking at the one piece loomis CC 12wt?
I had a chance to cast one this past summer and was very impressed. Incredibly light for the available power.
The only thing I didn't like was the new style guides that make a horrible squeeking sound when the line is stripped. On the plus side the new guides are incredibly light weight and indestructible.
Sailfish do a pretty good job of wearing themselves out and tend not to sound like marlin and tuna. Large bulky flies require a lot of grains to get them to the target.
Any well made rod of 12wt and above will work for sails but you will also need a solid reel with a first class drag.
When sight fishing, look over your shoulder from time to time, you never know who's behind you