Being that you already own those reels, I'd suggest practicing with the Shimano Torium 20 (that's if, the free-spool is in perfect working order?). At least the Shimano has a spool tension dial on the reel to aid in your learning curve. Once your casting in the 60-80 yard range, consistently without back-lashing, I'd switch to the Newell for those additional 20 yards.
Like I said, I wouldn't suggest the Newell unless you're already casting at an expert level; as there's no spool tension knob. It's the way it should be; incredible free-spool with no breaks. The Newell is hard to beat (free-spool wise), unless you're catching big Yellowtail on the surface-iron with heavy drag...all the time. Or, plan to fish the surface-iron with spectra (this reel isn't made for that kind of stuff). If you're doing either of those things--- the drags just go out when the entire ocean erupts in front of you. Which isn't a big deal either if you have two jig-sticks on board, like me
.
Since you have a Daiwa Sealine 50 already (which has great free-spool as well), that's just another option for you. For me, even though the Daiwa Sealine 50 has great free-spool, it's a little too wide (same width as the Torium 30). Remember, each cast will be a direct result of how well you wound the line on. It's just more challenging to wind the line on perfectly with a wider spool. It's also more challenging to wind your line on perfectly with a reel that has a low gear ratio---if, you're trying to wind fast. Which is common on a lot of jigs to make them swim properly. For that reason, I prefer not only the perfect height and width of the spool, but a 6 to 1 gear ratio.
In my opinion, the ultimate goal should be training your thumb to adjust to each swing. While spool tension and Magic Cast will help in the early stages of learning to cast---eventually, you should be casting with no breaks on the reel at all.
Above all, like I said in my previous post---it's about one thing: catching more fish. And the surface-iron is a great tool to achieve that goal. While I have all conventional reels, without breaks or magnets used on any of them, my eyes are forever open when it comes to catching more fish; the sky's the limit!
I still like to think, I improve every-time I'm on the water. And if a twenty-foot, hot pink, upside down coffee grinder with spectra can cast 200 yards---you might see me swinging one before it's all said and done.
