I would opt for 22k gold plated for durability and looks with a clearcoat added for protection.
Costs more than brass but looks better in terms of lustre and the wow factor.
Prices will vary greatly between businesses so it pays to shop around and get quotes (even from interstate). Many platers will quote top dollar just for the annoyance of having to do a small plating run of two or three ramps whilst for others that is their bread and butter. Expect to pay between 60-90 per ramp for a good quality job in genuine gold plate with polish and clearcoat and high level finish.
I would recommend A Class Metals in Adelaide or Precision Plating in Melbourne. Both offer plating and clearcoating so it is a one stop shop.
This is the set I did for one of my MM restorations with plating from A Class:
Close up shot. You can't even tell it has been clearcoated.
