Most salmon guys select regular ol' leadcore (available in many brands) in either 18 and 27 pound test. I've never tested it, but it probably has a breaking strength close to that. Sink rate is about the same, either way, so I'd go with 27 - especially on a five color.
Tuf-Line Micro-lead and Sufix Advanced both use braided line as the sheath and their breaking strength is much more than what the package says. Don't know about Sufix, but Tuf-Line shows on their website their 18#, actually breaks at 53 pounds. I would guess Sufix Advanced is similar.
TL-Micro has the same sink rate as standard, is much thinner, however, so you don't need an oversized reel.
Sufix Advanced is touted to sink 30% deeper. You can use less or just adjust your thinking and get it deeper.
On conventional leadcore, the Willis knot is great for joining LC and mono or fluoro. I've had trouble putting 20# mono/fluoro inside the core on Tuf-line and Sufix Advanced so I pull out a few inched of the lead and use a double uni.
If you can find an issue of Great Lakes Angler magazine - the June/July issue - just being mailed details this in much more "depth" and a follow up feature in the August September issue will detail fishing strategies using LC.
Go to
www.GLAngler.com to subscribe.