Simtex Seat Protectorant and Aftermarket Seat Covers

[Fairway]

My 20LLG sits broadside due west when docked and the bow seats catch a lot of sun when the cover is not on.
Anyone have any recommendations on a protectorant to apply?
Amyone had any luck with aftermarket seat covers to keep the sun off?
Im in a rural area and there arent any marine sales/dealers/upholsterers within 50 miles. Was wondering if anyone might know a decent light canvas/material (not a plastic tarp) that I might be able to pull across the front and attach (trampoline style).

 

[Michiman]

I assume using your full cover is a PITA but it might be worth the extra effort, particularly with your lack of access to a canvas shop.