An eight foot would work but I would go 9 or 10 if you can handle it. You'd be surprised how much more casting distance it will make. The penn fierce 6000 should be fine regardless of the rod you choose. Good luck...

I agree with the other two answers - use the longest rod you can handle, it will help with casting distance. A fierce 6000 will work, but I prefer penn's slammer series because they hold more line. I also like to use power pro (braid) with a heavy (50lb.+) flourocarbon leader because it lets me put more line on my reel. Remember tarpon are going to run and if you're not in a boat to chase them down, you're going to need as much line as you can get.