15amp fuse jumper

Hi all, so just bought a mini pioneer d1004 amp to power my new door speakers  im running a gamma 4 headunit as I like the more standard look. The headunit has a 10amp fuse but the mini amp is 15amp fuse. The mini amp should be powered from the headunit but given thats only 10amp and the amp is 15amp i was wondering am I best taking the power from somewhere else. Maybe run it back to the fuse box and use a fuse jumper like below? What would be the best fuse to put something like this in to think dash clocks is 15amp?

Ok so got a fuse piggy back. Question is what fuse is ignition hot so amp is only on when ignition is on to stop it draining battery…. rear heated window?