Custom development board for arduino

[visionofast]

Hi everybody,
I need to design a custom developement board for my arduino UNO and MEGA to mount multiple modules at the same time.
for example a combination of ESP8266 ,SIM800 ,IR tranceiver,... and so on.
well,it's necessary to match the dev board at the same size of arduino's dimensions precisely.
Is there any pcb designing software that includes arduino as a predefined part in library and part list?
any other tips and recommendations is welcome.
thanks

 

[Nigel Goodwin]

DesignSpark (which is free) has a tutorial showing how to create a template for Arduino, and as part of that tutorial it references a standard Arduino layout.