I have an sv650s master cylinder and it should work great on a thrux, it's bigger in piston diameter so it should be a nice improvement, especially coupled with a 6 pot caliper.
If your bike is a Thruxton(04-08), Speed Triple, Sprint and Tiger ( all the same), will be a bolt -on replacement.
If you have a Bonnie the Rocket 3 it's the one.
If you have an 09 Thruxton also the Rocket 3.
I hope this help.
I was looking for a larger than stock master to go with my Pre-tech 6 piston calibur. I got the master for a 1000 speed triple. The stock thruxton is 11mm. The speed triple is 14mm. I am very pleased with the results.