Good vendors for replacement alarm panel/keypads?

["Bob" <bobnospam1@xxxxxxxxxxxx>]

My friends ADT system died yesterday. From all I can tell, the main control
box died - All keypads just flash LEDs bottom to top - no keypad response -
disconnecting battery and transformer and reconnecting does nothing.

I would like to know what sites people would recommend for replacement panel
and keypads. Hopefully, I can use the current wiring and sensors/pirs with
new equipment. |Also, what brands do people recommend for self installation
by a talented do-it-yourselfer.

Price is a consideration.

Bob