Choosing fly line -- Redington CT 9' 4wt
So, I'm new to fly fishing at about a year and half of experience. I just upgraded my packaged Quarrow 8'6" 5wt to a Redington CT 9' 4wt as my 'big' rod after a lot of research (I also have a 7'6" 3wt for small streams) -- plus it doesn't hurt that they can still be had for around $100 since the Tempt came out.
As the subject states, I need a fly line. I'm going nuts searching through threads for recommendations and would love suggestions specific to this moderate-action rod. One thing I've seen said numerous times is NOT to go with a line that's 1/2 weight heavy, but I'm not exactly sure how to know or not. If I were forced to pull the trigger right now, it would be for either the Cortland 444 WF Peach or Sylk.
Some people say 'don't worry it, any halfway decent name-brand line you get will be okay' while others say 'don't skimp and try to save $20 on one of the most important parts of your setup'. I probably fall in with the latter crowd. I'm willing to spend the money if it'll be worth it, and if the line presents difficulties that are a matter of technique, I can learn/work to overcome them.
So... any suggestions?
 Floating for dries, primarily.