Hi,
This is how I've done mine, It's made from 5mm ally, all marked out and drilled by hand, countersink is done using a "caged" countersink to keep them all the same depth, then blasted to make it non slip.
As Craig has said profiled parts are easy to do and many places will do either water jet or laser profiling from a DXF file, we use ICEE down here and have a lot of parts cut from stainless, ally and wood.

Paul