Question About Re-targetting and what not

I would like to preface I know there are the youtube tutorials on how to do retargetting but I wanted to know if #1 I can use an autorig from mixamo and retarget a character from that to use the ue4 skeleton or is it better to create your own bones/rig (Not my area so not sure what is actually needed) to then retarget?

Also if someone happens to own the zbuilder for 3ds (HUMAN ZBUILDER) and can point me in the right direction with that and getting the character prepared for UE that would be awesome too!