On a Spyder, a long bolt and a spacer through the beam mounting holes works very well to mount on the back side of the beam. Keep it low to stay away from tie-rods and steering box.
You can also mount the pump and pre-filter in front of the beam, unless you have a front swaybar. That can be snuck in there also if needed.
I think the front is best, as the hose from the tank can go over the beam and stay 100% away from the steering components.
In my Spyder, I have a custom anti-sway bar that I made. I have dual horns, and a filter and pump for the gas heater in front of the beam. Behind the beam is the pre-filter and EFI pump. The post-pump Subaru can filter is in front of the beam.
It can get pretty packed up there eventually. To start I had just the horns, pump, and filter.
I recommend a rotary self-regulated pump(3 to 3.5 psi) if using Webers or Dellorto carbs. No need for the extra complication and connections with a external regulator in the back.