Lews BB1 Pro in 8.0:1 is the best I have ever used. Holds a pile of 20lb line and can crank the drag all the way down. Option number 2 for me would be the Super Duty LFS frame, I love that reel, only downside is you can't hold quite as much line.
Old "greeny" curados are fantastic for carolina rig
That's exactly what I use. Not the real old ones, but E7 Curado. Just make sure you get a fast retrieve reel, 7:1 or 8:1. You lose some fighting power but it's nice to get it back in and chunk again instead of spending all day winding. I fished C-rig for 5 hours yesterday, love that presentation!
Another + for the old green Curado. I use a B series 200 Curado. Holds plenty of line, decent drag, casts a mile with abec7 bearings and I own several of them. (no additional cost)
I like a 8.0.1 lews bb1 pro holds plenty of line too
Even though this reel has an 8-1 gear ratio, it feels like it has plenty of power because of the large handles it comes with and you still get plenty of speed and plenty of line capacity.