Forget about a Carolina rig for trout. The best way to use powerbait is with a small treble or single hook. Use a slip sinker in front of a swivel. Then when the trout hits the bait there will be little resistance and they won't spit it out.
Pather martins can work well in lakes and streams. It depends on the location.
Isn't a slip sinker in front of a swivel essentially a Carolina Rig? Of course you aren't going to use a 3/4 oz slip sinker as when you are going for bass. 1/8 oz or less for trout.
I am thinking I'll need some light fluorocarbon. What size do you use, 4lb, 6lb 8 lb?
I've had horrible results with flurocarbon on spinning reels (assuming that is what you are using). Tangle city. I loaded several reels with fresh floro and within weeks had stripped it off and replaced all with mono.
For smaller, easier spooked stream trout, I use 2 lb mono on a UL outfit. For most other trout, I go with 4 lb mono on a L outfit. I wouldn't go heavier unless I was in a big lake going after lake trout and monster browns, in which case I may go to 8-110 lb test on a ML outfit.
If you are concerned about line visibility then you can always tie on a flurocarbon leader.
The Panther Martin is an excellent trout spinner. Rooster Tail, Blue Fox Vibrax and Mepps are also good. Try small spoons also work well. Little Cleo, Kastmaster and Phoebe.