Weather tight access panel for floor ??

[JimDirt]

Does anyone who make a access panel/door like what is shown in the 3rd post down at the middle left of the image ?? http://67-72chevytrucks.com/vboard/s...d.php?t=691929

I was wanting to have a access panel for the master cylinder on the drivers side floor , that was large enough to actually get your hands in , instead of the tiny access hole that is stock on my 58 , and to have the battery mounted under the floor on the passenger side (access thru the floor like shown in that picture in the link , or in the side of the kick panel) where the battery would be mounted along the frame , but with easier access than crawling under the truck to hook things up or charge battery , etc , something that i can install without losing the integrity of the floor , so if someone stood on the area it would not collapse , but that is also weather tight and preferably has a twist handle/latch so you don't need tools to open it (similar to what it looks like they have in the picture in the link )