Best paint for car floor

[tawelfryn]

Hello folks.
What would be the best treatment of the underneath of a classic cars floor, after its been sandblasted down to bare metal?
I was thinking of a zinc primer first? Any good? followed by maybe stonechip and then body colour?
Or is there a better paint/treatment to protect the underside?
Cheers

 

[Zampa]

Zinc phosphate primer will be ok then underseal..

I wouldnt bother with any coloured paint you wont see it anyway.