GF for Small Business with 5 static IPs - How to configure routers???

I must be missing something in the (lack of) documentation (which feels like this), because this really shouldn't be this hard.

We currently have a Netgear SRX5308 plugged into the Fiber Jack, and will have an assortment of other routers connected to the LAN ports on the SRX5308 (once we get it configured!), but currently only have one (an Asus RT-AC87U, which I do want to be set up with one of our public IPs).

Instead of going through my current setup which is definitely not correct (though I can tell you some of what I've tried if you ask), does anyone here have a step-by-step guide on how to actually set this up?

GF support hasn't been very helpful, mostly just sending me to the aforementioned documentation, and Netgear tells me to contact my ISP for docs before they can help.

Thanks in advance!

edit1: forgot a small detail