I used some cheap aluminum channel from Home Depot and installed two years ago. Cut it to length and used a grinder/dremel tool to contour the cockpint-end to match the profile of the hatch around it. Looks fine and would send a photo but for the 3-4' of snow in the club's yard.
If you go this route, be careful to match the exact fastener size of the screws holding the aluminum in place - I inadvertently went a wee-bit larger and it cracked the gel-coat.
Also, take some time to *really* countersink the screw heads in to the aluminum - mine stick out slightly and it makes the hatch rattle when it slides.
If you're really keen to see the pics, let me know and I will snap a pic the next time I check on the tarp....
