Help with fuel system design for LS1 install

[brossow]

[ Also posted this on LS1tech but looking for opinions from any possible source. ]

Trying to piece together the fuel system for the LS1 ('99 Z28 donor) that's going into my '72 Chevy shortbed. (This is my first fuel-injected project, so please be gentle with your advice and criticism.) Here's what I have so far:

• Custom gas tank with 3/8" NPT inlet and outlet
• Walbro 255 GSL392 external fuel pump
• WIX 33737 (Corvette) filter/FPR

I'm planning to do braided fuel line with AN fittings all the way from the fuel rail to the tank. I already know what fittings I need for the 'Vette filter/FPR and fuel pump. I need to know the following:

1. What size line should I be running throughout? I'm assuming AN-6 will be appropriate but I also know what happens when one makes assumptions.
2. What fitting(s) will I need at the fuel rail?
3. What is the proper layout from gas tank to fuel rail for the lines, filter, and fuel pump? My assumption (see disclaimer above) is that I will have the 'Vette filter with the inlet and return lines plumbed directly to the fuel tank, then line from the 'Vette filter outlet to the fuel pump, followed by another line up to the fuel rail. Is this correct?
4. The vendor for the custom gas tank says I need a 90° anti-siphon valve for the overflow fitting on top of the tank. The tank came with a 90° barbed fitting to go to a 3/8" hose, but that can be removed. What exactly should I have here? Searching for an anti-siphon valve via Google hasn't given me anything close to what I think I would need.
5. Am I missing anything?

Thanks in advance for the help. I have virtually no local resources and so I'm ordering everything online. Really want to make sure I get it right the first time and don't end up missing a fitting or buying stuff I don't need.

Thanks again,
Brent