Great project!!!
Dreamcast really deserve a SOR4 Version, lets make some justice!
i have made some test with Teenage Mutant Ninja Turtles: Shredder's Revenge in DreamBOR and it can be a good project to Dreamcast, but now iam focus on my personal project Cyber Squad Valkirias.
One question about your project, why you didnt use the SOR4 original background?