I doubt that an intermediate line will get you down where you want to be unless you are in very soft water. A sink tip line is one answer, but they can be unpleasant to cast. Also, for the depths you are talking, Rio makes what they call a Versileader, which comes in 7' and 12' lengths, as I recall and sink rates up to 6. ( See Dave's thread http://www.flyanglersonline.com/bb/s...ad.php?t=33419 )

I would suggest a full sinking line, and for the depths you are talking it would probably take a Type 3 or more to do the job. Here's a link to a Rio Mainstream full sinking line that comes in Type 3 and Type 6. I really like a Class II full sinking line for streamers, but don't tend to use one for nymphs because it seems to me you would have difficulty maintaining a good drift, unless you were fishing some very steady and even currents ??

http://www.rioproducts.com/product.php?recKey=53

I think the Mainstream lines by Rio run around $35 ( but I haven't checked for a while and could be wrong about that ).

John