Wildfish,
I find that an 8WT covers pretty much all my heavy freshwater fishing (except muskies) and works well for shallow water salt (bonefish, stripers, reds, etc). I doubt that a much more expensive rod will improve your situation much. It should be recognized that large salt flies tied with dumbell weights or other added weight aren't likely to ever cast with the beautiful, arching leader turn-over typical of small, weightless trout flies. It's a different ball game. And yes, the rods are heavier. Trout guys often experience fatigue when they switch to bass or salt gear. One bit of advice I always suggest to new bass/salt guys is cut out the false casting. Practice casting in the back yard and learn to really shoot line. I think a lot of trout guys never really learn to double haul and shoot line and they wind up over false casting and wear themselves out on the water.
Don't give up on your 8WT.