Creating a belly pan diamond pattern

[mman1506]

I'm trying to figure out the best way to do a aesthetically pleasing 254 style lightening pattern on a belly pan. It seems like the fill pattern tool would be the best for this but I can't find a way to allow the diamonds to be cut by the boundaries (half triangles around the edge).

I also assume that the best way to make a belly pan is first doing the pattern then extruding your electronics mounts?