You may have to buy a standard circular mandrel bend of the correct height/bend radius, slit it down the middle, and butt weld in flat pieces to create the oval cross section.
I'm not aware of any suppliers that offer bent ovalized tubing in the configuration you want, but it doesn't mean they aren't out there.
My 1969 Chevelle
- Procharged/Intercooled/EFI 353 SBC, TKO 5-speed, ATS/SPC/Global West front suspension, Global West/Edelbrock Rear suspension, C6 Brakes & hydroboost, and other goodies including a crappy paint job.
Twin Turbo LS2 in progress...