on our trip, slow jigging with hammered diamond jigs produced just about all the jigged fish. personally, i like conventionals better with this method. long or short rod is up to you, i was using the 7'6" OTI, 5'8" jigging master and a 5'8" Seven Seas rod. All worked well. dave used a spinning rod for slow jigging, and did just fine as well.
I'd also bring the setup glenn mentioned as well if possible.
I'd take your 8k/OTi300 and OTi600/665n. That will give you a conventional and spinning outfit. That's all you need. Most jigging down in Panama isn't in real deep water. You probably won't drop in water any deeper than 250'. Most of the tuna are found on plateau's as the tuna come from deep water onto the plateau's. When I was there the YF's were caught in 129' of water.
I would work the hammered jigs slowly. I didn't have much luck speed jigging the hammered jigs. Macho kept telling me "Rapido, Rapido". After many drops with speed cranking I started doing slow long lifts, and Macho would tap me on the shoulder and say "Rapido, Rapido". Rapido did work for me using long skinny jigs but I caught nothing speed jigging the hammered ones. You don't need any jig heavier than 320gms. Even with the strong current, I could hit the bottom with 200gm jigs constantly. I had better luck fast jigging the OTI jitterbel than any other jig.
Good luck. Like stated above, we all have our styles. Adjust to what works and experiment with different jigs. Don't forget to take some casting iron type jigs. Those did better than the vertical jigs most of the time if we weren't sitting on a particular rock and were drifting.