Can someone point me in the right direction?
Ive flashed a modded firmware on a mates ps3 but the console will be using aftermarket fightpads not the usual ds3 controllers.
How would I change the button sequence to bring up retroarch menu as L3 + R3 are out of the question?
In very recent builds, you should be able to go to settings > input > menu toggle gamepad combo and set it to one of the other available presets, like down+L1+R1+Y.
Ahh Im using an old build, 1.0.0.2.
Thanks Ill try the latest build 
EDIT. Updated retroarch to one of these beta builds and after tinkering with different settings its perfect.