Drilling into painted floor, ideas to stop any rust starting

[100BUR]

It looks like the only way to secure the fuel supply line and fuel return lines on my fuel injection conversion is to run booth hard lines up the passengers side floor, into a bracket with AN6 bulkhead fittings then braided hose for the engine bay connections with aluminium fittings.
I don't want any jubilee clips

This means the floor will need to be drilled to secure brackets for the hard fuel supply and return lines.

I'm nervous about drilling the floor and the possibility of rust appearing after use.

Any ideas how I can do this, possibly sealing around the bracket screws inside and outside the car to help stop any potential rust.

The car is wax oiled underneath and has carpet,backing and sound dealing fitted inside.

The floor tabs as fitted are not helping to bring the pipes out in the right location

[Tupers]

This is how I’d do it.

Degrease the areas you need clamps.

Drill and deburr the required holes.

Dab some zinc primer around the bare metal with a cotton bud or similar.

Dab some 2K colour over the primer with a cotton bud or similar.

Apply a small amount of Sika 221 or similar to an ideally stainless steel rivnut and fit with a rivnut gun.

Apply wax oil to the area the clamp will cover and bolt on clamp with stainless steel hardware and an anti seize compound.

[100BUR]

Thanks for the reply and info
Cheers