As I understand it, the only reason you would need bitsetting is to be able to play +R disks in older players (or in gaming systems). With the cost of new DVD players as low as ~$30.00...Why not just purchase a more modern player, rather than trying to find a drive that supports bitsetting?
Are you having problems with your 2500A? Just asking because I have no issues with mine with the current firmware. I guess my philosophy is...If it ain't broke, don't go trying to "fix" it. Current firmware is working just fine.
Just my 2 cents.