I want to develop a Firefox add-on that change the whole UI, something like write new chrome://browser/content/browser.xul file.
I'm js developer, have no experience with add-ons development I didn't find something like that at add-on sdk documentaion
AFAIK, such functionality is available through XUL overlays in plain old non-bootstrapped Firefox add-ons (those, that need restart of web browsers to install). If it is OK for you, you may just create such add-on. It is as easy as writing ordinary HTML (XML in fact). Look for Chrome Registration and for XUL Overlays on MDN for details.
If you are required to create bootstrapped (restartless) Firefox extension or you must use Addon SDK, then your only option will be to watch newly created browser windows and modify them manually. In that case you are not able to modify the source of chrome://browser/content/browser.xul file.