You have alot to think about and your Heli experiance helps.
Here is some reading:
[link=http://www.mycoolrc.com/FAQ/firstrcplane.html]Beginner First Plane[/link]
You may want to go the cheap electric route, Undoubtedly, you already have a sim if your heli flying so that will help alot. My advice is NOT to jump out and spend $400 on a Nitro plane but to give it a try with an electric, but not something as small as the tiny parkzone BnF stuff.