There are many different sites that sell rc plane engines. Some include: http://www.hobbypartz.com and http://www.towerhobbies.com/. There are others if you look around.
There are many good toy/hobbie store online that would sell an ARF RC airplane. just by doing a imple seach i found one... why not check out www.towerhobbies.com/
You can buy inexpensive rc airplane batteries online at www.all-battery.com/rcairplanebatteries.aspx. This is a great store to find all cheap batteries online.
There are several places you can look. It does depend on how high of a quality of an RC airplane that you want. Check out this place. www.nitroplanes.com
Online, there are many websites where electronic toys could be purchased from. The most popular, Amazon, will most definitely have a RC airplane. Also, check out a department store site, they sell the same things in the store as the website.
You find RC car engines online at many different retailers. A good retailer to check out is eHobbies. There are many different models of engines to choose from. Here is the store: http://www.ehobbies.com/
Here you can buy all kind of RC Helicopter and RC airplanes http://www.agehobby.com
All engines are bad on the environment, they exude used chemicals once fuel is burned. But with technology progressing as it is there is less impact on the environment today than there was 20 years ago.
Micro RC airplane kits may be found on the site Microflight, or they may be located at Hobby Lobby, Ebay, Amazon, Thirty Thousand Feet, and Toys R us.
It is best to get flying lessons so you do not destroy an RC airplane because it is difficult.
Your larger hobby centers should be able to sell you one or order it for you.
The best brand for RC airplane parts are Blue LiPo, Gens Ace, Sky LiPo, A123 Systems, Exceed TX and FlySky Airplane/Heli TX. They were all reviewed as the best brands of RC airplane parts.
RC Airplane simulators are similar to video games. You put a CD into a computer and it brings up an application that allows you to simulate flying a real airplane.