A diagram like this? (see attachment) Nothing is labeled by name, but it may help you to identify missing parts, and most places seem to know what you mean when you reference the WA part numbers on that diagram.
Also, keep in mind that many of the small misc parts are interchangeable with real AR-15 parts, or can be made to work with a little bit of fitting. That opens up a whole other supply source from you, since AR parts are cheap and easy to find in the US. Things like the grip, takedown pins, gas block, dust cover, stock (depending on what reciever you choose), etc can be sourc