Battery Relocation on a new build

[ChadW]

Good afternoon...lengthy question...

Building a full custom 66..I just mocked up my Slosh Tubz and now realize that you can not use the stock battery location on the core support.... I have one battery that is mounted passenger side behind rear tire...that battery is for my air-ride and stereo. I bought a battery isolator kit to hook up so my alternator can charge both batteries, and the air-ride/stereo will not draw from my starting battery...I have a raised bed floor that opens and will be mounting my main starter battery under it, towards the front of the bed..I will be doing a complete rewire of the truck as well when it comes to that time with the American Autowire Classic update kit. So...My question is, what is the proper way to relocate my starter battery to the bed area, and make things easy for me as well when i go to do the new AAW harness...Do i run battery + to starter and Battery - to the engine block like they are now...how do I, or should I, get a + stud under the hood for other things that may need power? This is a good ol' SBC with HEI...any help appreciated greatly... Im a newbie to the electrical side