Skagits are the easiest way of throwing big and heavy flies and heavy tips. They are easy to cast providing you are able to make a Double Spey for downstream wind and Circle Cast or Perry Poke for upstream winds. In truth, I prefer a Skagit set up for Spring & Autumn fishing as I can control speed and always know exactly where the fly is, something you can never be sure of when fishing a full sinking (or even intermediate) head. Note that a Skagit is a tool for a job, not a general purpose all round fishing line. To use one in the summer with a floating tip on it and a small fly would be like trying to tap in panel pins with a 10lb fence post hammer.
To explain a little about shooting head set ups...... The idea is that the whole head (the AFS) is almost all held in a D loop when you deliver your cast and only the tip of the head and the leader is on the water as an anchor to maintain tension in the system for making the cast. Almost all shooting heads are designed for use with long leaders, they cast better than way. If you want the fly to go down, part of that leader is made up with a Versi / poly leader (Rio / Airflo terminology), usually 10' for me and to that is added a short length of tippet. For a full floating set up use a decent tapered nylon leader such as the Rio 15' ones and add a couple of feet of tippet to the end of that.
Not all Shooting heads will cast the same, AFS is back biased in terms of weight which means it is easy to cast as all the weight in under the rod tip but it is not the greatest at turning over big heavy tubes on the end of a fast sinking poly leader and it tends to hold a poor shape in the air and fly / land arse down. The MacKenzie shooting heads are still the best all round heads IMO, they are little longer than most and not quite so back weighted, they fly better than an AFS and are happier to turn big stuff over. Again, they are designed to be used with poly leaders or long tapered mono leaders. Due to the difference in weight distribution, a 44g MacKenzie head feels about the same to cast as a 10/11 (42g) AFS
Then you have Multi Tip shooting heads like the AFS Tracker (now Scandi Versitip) or MacKenzie Multi tip shooting head or Guideline DDC (probably other brands too) that are basically a short rear body that is looped to a tip which forms the front taper of the line. These are proper fly line style tips, usually 15' long and made on proper fly line core and are generally significantly heavier in terms of physical weight than poly leaders used with full length shooting heads. These lines bridge a gap between Skagit lines and Scandinavian style shooting heads, I tend to use such lines without a polyleader on the front of the tip, just a short length of tippet to my tube. I use the tracker a lot in the early spring when the water is not big enough / cold enough to need a Skagit, again these things are fairly industrial and probably not the best thing for use with small flies where delicate presentations are required.
There is such a choice out there now that really, unless you are dealing with or in salmon lines on a daily basis, the best advice would be to try and get a shot of a few different lines on your rod. Things are becoming increasingly complicated with Salmon lines, the developments should make fishing easier but the choice is absolutely bewildering for many anglers and mistakes are not cheap at £50 for a head plus any ancillary items!
What are the Snaeldas tied on? copper or aluminium do they have cones on them and what is the overall size of the biggest ones?
Cheers
Ben