MAME control panel overlay

[JustPaul]

Hi All,
I am building my own MAME cabinet.  Currently i am trying to find a 4 player CPO.  I have checked out numerous sites, however there is a very small selection.  So, if anyone out there knows of a site with a nice selection of 4-player layouts please let me know.  

Also, i see people are creating their own control panel overlay's.  If someone can tell me how to that, it would be great.

Thanks in advance.