Excellent site for on designing and building your own miniature scale aircraft for indoor flying. This site is mainly aimed at people new to this kind of aeromodelling and those who want to design and build their own machines. Includes plans to help you get started, and you can look at the pages on indoor planes and park flyers to find something similar to what you want to build. This will give you an idea of weight, motors, rubber sizes, control systems etc based on something that works and should save you some development headaches. Thanks Rick! Link.
Design and build your own miniature scale aircraft for indoor flying