Quiet board here. I primarily fly fish for redfish while standing from a kayak. Iíve also done the same standing in boats.
Just about any set up can get it done. Iíve used anything from 4/5 weights to 10 weights saltwater fly fishing from a boat or kayak. Bigger fish, bigger flies, more wind, more rod is usually needed. I tend to like shorter rods, 7í6Ē- 8í, fishing while standing in a kayak or boat. Itís just easier to land fish with a shorter rod and less tiring to cast. Plus, itís more like a baitcasting set up and short fly rods have a lot of built in accuracy.
Reel just needs to be able to handle saltwater exposure. Anodized and machined Aluminum holds up well. Sealed, synthetic drags are nice. Fly line is pretty key. I like SA and Airflo. There are lots of tapers that work. Leaders are easy to make from ordinary mono or fluorocarbon. Flies vary. Hook point up types are nice around bottom structure.