Tayzay,
I've got a pop top and enjoy the standing head room when at
anchor. I always seem to damage the latches, but don't have leakage issues. I don't know of any source short of having a canvas shop make one for you. My tent is blue Sunbrella that adds screened zip windows and companionway access screens and rain flap doors. I have several pix posted
Whttp://picasaweb.google.com/Jumaggafanny/Chimera#
here and what Helms 25?