I keep a pack of the Orvis mini-sink tips with me at all times. I use a sink-tip and they give me the extra punch I need when I have to go a little deeper.
I tried the offshore angler line that Jim mentioned but dumped it for the reason that he pointed out -- the loops get hung up coming through the tip, especially when you're bringing a fish in close for a landing. Then, when you're casting again, you have to get it BACK through the tip -- that little hang-up was too nerve-wracking for me.
re: STH -- I have two of their reels, one for my 4 wt and one for my 12. No complaints, sturdy with good drags, seems like kind of a sleeper brand. I may look into their new saltwater series next time around...