Bed liner or Rubberized Undercoating on the cab floor?

[IRN BRU]

I am going to paint my cab floor. I currently don't have a carpet or rubber mat on the floor and I like it that way and its probably the reason why there is almost zero rust on the floor and corners. But I am planning to tidy it up and hopefully soundproof it a bit by rolling on some bed liner or rubberized undercoating but I don't know which to do. Spraying is out of the question as i don't have the equipment and my budget is only around $100.

Should I undercoat the cab floor for sound deadening then use bed liner on top of it for wear strength? Or would the undercoat hold up on its own? Or would the bed liner sound deaden enough by itself?

Reservations I have are:-

Rubberized Undercoating is maybe not hard enough and stays tacky without fully drying/curing.

Bed liner is too rough and will hold a dirty footprint mark for eternity. So I would need to find a brand that has a smoother finish. Maybe a gritless type?!?

Has anyone had experience with this and maybe have any tips or suggestions. I really have to get this right first time as cleaning up a mistake with either of these options would be as "welcome
as a fart in a spacesuit"