SE operating system designing

i dont know under which category i should post this topic.

Well am interested to do a project on mobile OS. Can anybody please give me some ideas, sources, examples of open source operating systems(with code) etc.
please also give me the language and platform.
A good set(any brand) which is well suited. well i have seen only SE phones with flashed OS.if possible with other brands also,then how to do it?

its a 1 year project. so i would be getting much time,i believe.

Any one have any suggestions, feel free to reply.
please help me.