RE: Help me choose please....!!!
Plenty of folks will disagree with what I'm about to recommend, but that's all part of the fun.
Since you've been flying helicopters, you're already experienced with RC flying and should be able to start out on a "second" plane if you'd like to.
Sig kits are available to you; they also are very high quality and come with great instructions.
Based on these facts, I'd recommend that you build a Sig Four Star or Mid Star kit as your first plane. They are easy to build, they fly great, and they won't be so wild in the air that they should give you too much trouble.
Good luck and good shopping!