You are a gear fisherman who wants to get into fly fishing? Well then, you just can't have too many rods =)
*** You Have Been Warned!!! ***
As noted a good store can demo and have you casting rods before you buy. There are also tons of classes / courses to take to help you decide if you really want to fly fish or not.
Personally I do not think you should switch to fly fishing, just add it to your arsenal. Depending on where and how you like to fish and how close you are to crowds, fly fishing is not always the best choice. I.e. several weeks ago I was out by Cap. River and was the only one fly fishing. Even though I was not in anyone's way I felt like daggers were hitting me.
For trout fishing if you plan on stock lakes and the likes with smaller fish, 3WT. If you want to do that and possibly target bigger fish in the interior, 5WT.
I also second the suggested Amundson Top Fly rod in 5WT (not 6WT).
In case you are curious I use an older Pflueger Summit IM6 6WT for pinks and coho in tidal waters.