Forgot to mention my experiences…
I compress high school football games for a local cable channel (to give to the teams). These are mutli-camera truck shoots. Video cutting, graphics, slow-mo playbacks…everything you’d see on any football broadcast.
In most cases the videos are about 2 hours, but sometimes they run closer to 3. In those cases I’ve gotten 3 hours of video on a DVD-4 disk, even with all the movement and cutting!
Now, it’s close to VHS quality at that point, but the client is happier with that than with paying for 2 discs or a DVD-9 disc. So they live with the quality loss when games happen to run long.
So my point is, if I can fit 3 hours of a sporting event on a 4 GB disc, I’m betting you can do 5 hours for a disc twice that size. That’s less compression than mine, first of all, and secondly, your subject matter should compress a lot smoother and look better at lower rates than my does.
It’s sure worth the time to compress a test. And be sure to burn the test to a disc and watch it on a TV. It’s nearly impossible to judge them on the computer screen.