after getting no replies from anyone else, i'll post here

the yellow wire on the left is what i have in the car right now to supply power to the head unit
the head unit then supplies power to the 2 head rest screens and the remote powers the amp

the wire on the right, orange with the black stripe, is the wire that's come with the loom for the new headunit i've got
this wire also powers the dvd player under the seat, both headrest screen, the 6 changer 6 box and the sat nav dvd player
the remote feed doesn't do these things

both of these wires need to be the memory feed for the radio so it's not a case of running another wire with a relay for a switched ignition feed

so my question is this

am i ok to run the power from the original wire? seeing as it's deemed to be suitable to run stuff as it's the patch lead between old and new or do i need to run a new wire?

what would you do?

because the wiring instructions to retrofit the stuff i'm fitting say nothing other than just plug and play it all together so am i over thinking this or am i playing it safe?

cheers