The T-profile mouldings sold by Outwater Plastics are pretty straightforward. Cut a slot with a router and push it in.
I'm curious about the PVC products. Are those just applied like laminate and trimmed/rouneded with a router? Is it practical do to this for a few desks or are there specialized tools required?
(I know wood is a perfectly good edge treatment too, but the end user does not want wood and given the curves I'm not inclined to argue!)