Yosh has the R-55 series "coming soon" for the '06 GSXR600/750. Haven't looked at any of the other dozens of exhaust vendors for that bike though.
As to the need of a remap, it usually depends on the bike and what the vendor recoomends. Some bikes EFI system will "learn" to adjust for the pipe, others may need the aid of a Power Commander or similar plug-in add-on to remap for the setup.