Design My Own Bmx Make A Custom BMX Bike Or Buy One. HELP!?

Make a custom BMX bike or buy one. HELP!? - design my own bmx

I want a new BMX bike and want to create, and buy my own bike design with different colors and everything individually. Even when I talk about the price and buy all interested parties the right or the wrong kind and size pieces. Could you please
1. A list of all parties.
2. A good place to buy the bike parts in Southern California or on the Internet.
3. Is it better to buy my own bike or one already.