Join the Multirotor subreddit. Will have all the info you need. Also, RCgroups is the biggest RC forum on the net. There is a drone section there that has the answers to any question you could ask.
However...Many 4in1 escs have a 5v out built into them, check if yours does and use that. You really don't need a pdb unless you are running 4 independent escs. Even that is outdated now though. You can get FCs these days that have everything built into one board. You just solder the escs onto the pads at the corners or use the 4in1 plug if running a 4in1.
I'm using this FC in three of my builds and its great