My first concern with the sharkskins is that they cost $8 each.
I wouldn't mind paying it if I knew for sure that they wont eventually stretch and fall off the spool like the rio tippet bands do over time.
I buy the cheapest Rio I can find with the bands Just to get the bands and spools. From there I spool Seaguar Flour in 2,4,6,8,10, pound test onto the Rio spools and bands. I did it at first as a cost savings but I've grown to like the Seaguar better then "tippet" so I use it exclusively now. I've tested it for several years and I'm VERY comfortable with its consistency and the break strength. I've yet to have a spool of it go bad. I can't say the same for tippet... Just bought a 2000 yard spool of 2 pound seaguar carbon pro for $19 on ebay. That should last me 10 years or better as long as I store it properly.
For larger line I keep a spool of 14,20,30,50 pound Vanish fluro or Ande Tournament line in one of those cheap Plano plastic spool holders in the boat.