As noted in the post you quoted, CD-Rs longer than 80 minutes severely violate the CD standard and are always sourced from low quality knockoff brands. You'd be lucky to ever get them to work in the DC. Stick with 80-minute discs, as most homebrew should fit on them. As for commercial games, your options are to either buy a GD-ROM or find a competent rip that fits on a normal disc.
I am just wondering. I bought a Japanese Dreamcast because the games are cheaper. But there are a couple games I want to play that are American only...