Recommendations

For tarpon on the fly an #8 is perfect, but both a #7 or #9 will also do, though some of the larger fish may outgun you on the #7. Glass or carbon? Fast or slow action? This is up to you. If you can hit 18 to 20 yards with a couple of false casts with your rod of choice, then you will do good.

If you are patient, then it is often a good idea to sit tight and wait for the school to approach the boat and long casts are not needed.  Cast short with a buoyant fly and as the fish get close start to twitch it back. The takes can be quite subtle.

However,  if you go up the rias and arroyos, the small channels that drain the mangroves, then a short #6 is a good option, but your #8 will also be fine. Think side, steeple, roll and bow casts, from 5 to 10 yards. The fish are smaller here, and as the water is often murky you can get away with much shorter leader. This is commando fishing where the rewards can be exhilarating.

Your #8 rod will be fine for permit and bonefish as well. 

Typical tarpon flies such as toads, gurglers, LT shrimp, peanut butter, bunny, minnow and cockroaches all in smaller hook sizes, max 1 1/2" long. The hooks must be the sharpest possible. 

For bonefish and permit typical shrimp and crab styles will be perfect.

Don't worry if you need any fly, Pedro can sell you some.