Rim lock striker plate

I have fitted a new Ledge and brace door to my outside cupboard. I am fitting a bog standard rim lock with a latch and key operated mortise lock.
I am fitting the lock to the inside with the door opening outward.
Does anyone know where I can get a long lipped striker plate that will accommodate the latch and the mortise lock.( I have found the Yale single one )
Surely this problem must come up all the time as the normal striker plates have a short lip that would only accommodate the door opening inward.
I could of course fit the lock on the outside of the cupboard with the hardware supplied .
But then entry to the cupboard is easily obtained by quietly removing the three screws that attach the lock to the door .

 

Hi
I'm guessing by sash mortise lock you mean this would have to be mortised in. the door is a 16mm tongue and groove ledge and brace door with no frame and will only accommodate the surface mounted rim lock . For security I want to fit the lock on the inside and with the door opening outward I need a long lipped striker plate.
I can buy a piece of brass plate and make one myself but it would be easier if I could just buy one.

 

Thanks I have already searched e-bay
Just to reiterate ..I am putting the rimlock on the inside of a cupboard door that will be opening outward .
The actual latch will be around 50mm from the front edge ..
I need a striker plate with an extra long tongue or the latch will be making contact with the frame.