5 cents for a resistor, 70 dollars for a TRE, 100 dollars for an ATRE
I recommend the resistor options, instead of wasting 70+ on a TRE which WILL probly NOT derestrict the bike. And an ATRE which may or may not work. I cant confirm that any TRE will work because i do know know how the electrical system is on the 03, on an 02 1st, 2nd, 3rd, 5th, and 6th gear are known to be restricted, i am unsure of 4th because i have heard it isnt, but not that it is (reason why im making a homemade tre for both 4th and 5th gear).
Look at the wireing diagram in the switchable TRE post in this section, it shows how to wire the switches and the resistors. I listed all of the resistor values on there.
I know on the previous models , and i believe its the same on the 03, you can get your ECU rev-limiter raised.
Last thing, If we all come to find out all the gears are restricted on an 03, the ECU change is the only way i know of to come close to derestricting it. But, you get better performance in the lower gears with a TRE
FatJap: have you dynoed the bike, or used GPS to verify that it is not restricted?