I have a fuse 30cm from the battery as well, if thats what your worried about. The 2 fuses in the boot are to be extra safe.
So the amps are fused themselves, the wires after the distro are fused the same value as their respective amps max, and the line from the battery to the distro is fused to the value of both amps.
And update -
The xtractors are awesome! The sound is much deeper/throatier, and I can feel the difference in low down torque. Very nice indeed.
There was only one snag no-one saw till it was too late. The wire on the O2 sensor needs to be lengthened by about 40cm, to reach the bottom of the extractors. I had to get my dad to go fetch the sensor, take it to an auto elec, then take it back to the exhasut shop, so thanks to the old man is in order.
Cheers,
C.j