Bed tank questions

We are running the excellent Facet Dura-Lift 12v Fuel Pump from Pegasus Racing pump in one of our IDIs, replacing the mechanical fuel pump. Truck starts much better now. That old 6.9 Bully is a most reliable runner. Started right up at 26F yesterday.

As luck would have it, we wound up with TWO spendy ATTA aluminum bed tanks for a pittance. One is in that IDI and the second I'm putting on my F550 7.3 tow monster. ATTA seems to be closed recently, hopefully it's just the ice storm. Their web pages on wiring, gauges, etc are incomplete, to be kind.

I'm wondering if one of you have plumbed in a bed tank and can help with a couple questions

1) I tested the sender and it's working fine. Ohms go up as the fuel level goes down. I would like a simple gauge right there on the tank. Push a button, get a reading, power it with a 9v.  Has anybody done that?

2) As it's a bed tank, its level is above the frame tank. If it had a low petcock I could gravity flow, but it has no low bung at all.  If i run a transfer pump, plenty are out there, but ideally it would be a pump that is only used to start a siphon.  Has anyone achieved that?  I don't see any sense in running a pump once the siphon is flowing.
UPDATE: Pegasus Auto Racing has tech support!  The Facet Dura-Lift that we used on our IDI will flow when shut off, so I can use it to start a siphon, then let gravity take over. If I'm in a hurry I'll run the pump. Question solved but your experience still would be helpful.

I also need to ask ATTA if I can clock the top fitting around at will, or if only 180 will  work. But for that I need reach them as their tech info web page is nearly useless.  I suspect it's only 180 degrees because the float will need clearance to swing in an arc up and down.