Ideas best battery location custom 57?

[mcarrel]

I am working on my wiring and I am trying to decide the best place to locate the battery on my 57 Custom project. I figure there are different opinions but with the wealth of experience here in this forum I figure I would ask. I want everything under the hood clean no battery and minimal wires showing. I am mounting the ECM for the TPI under the passenger seat and all the relays are going in the back corner behind the passenger seat. Here are some of my thoughts any comments or new ideas appreciated I am thinking I will use an Optima battery.

1. Behind the passenger seat (very crampt)
2. Under the truck between the frame and the left step. (Not very accessable)
3. Under the bed front right corner. Will have to build an access door.
4. other ideas?