I use both depending on the fly, regular or parachute... You can spin off a zillion flies off some of these new "genetic super saddles" that are very uniform in barb length over 12 or more inches!
What's important is that the "barb" length be proportionate to the fly you are tying... using a hackle that is appropriate for a size 14 hook on an size 18 hook is over dressing and some of the super saddles may not have feathers suitable for various size flies.... On a cape you will find shorter hackle feathers but a beeter selection in terms of size.
Saltwater capes & saddles are not generally usable for dry flies.
If you are looking to save money you can invest in "Indian necks"; they are cheap and will let you experiment with dry flies... I used them alot when I was a kid as I could afford them and they are passable for fooling trout.
Good luck! I'm Jealous that you likely get to fish for REDS and "Trout" etc. Haven't thrown into salt Water for four years now...