Kenny....One thing I have noticed missing in the above advice is that no one has mentioned that the end of the line...the fly and where you want to fish it in the stream. Scandi heads with or without Versitips (plus 3 or 4 feet of 10lb straight mono tippit) are meant to throw out small ( size 6 or 8 ) spey flies ( Silver Hilton, Green Butt Skunk, etc) for low water summer run steelhead. Skagit heads on the other hand were designed to throw monster flies (Intruders, leeche paterns, Prom Dress, etc) in heavy winter conditions when you want to get that big fly out there and down deep on the swing. In this case attaching either a 10 ft piece of T8, T11 or T14 or one of the combination MOW tips pluse tippet is the way to go.
Rule of thumb:
Scandi heads with or with out a versitip (which is essentally a sinking leader) plus a tippet for summer run fishing
Skagit heads plus a 10 foot piece of Tx or one of the variations that come with the MOW tips depending on how deep you want your big fly to drift.
I hope this helps.......Anne