Rack Surface Finish

I am sure you can go to HD or a lowes and look for different paint coats that you can apply.I don't believe the type of coat will affect the sound. I would look under auto painting or auto body work.

Powder coating is far more durable than paint, but also more expensive. Also, if you should ever want to remove it, it WILL NOT come off easily with sandpaper or even sand blasting. My powder coated steel computer desk had to be dipped in a vat of hydrochloric acid to remove the finish. However, if durability is key, look under "Coatings" or "Industrial Coatings".

Why did you remove the coating on the desk and with what did you replace the finish?

I should have mentioned that, as it may give you another option.....
The powdercoat was a grey/silver and I wanted the to see the bare metal instead.
Once the desk was dipped, it came out covered in scaly rust(that's normal). I used sandpaper and a wire wheel to remove all the rust and give the metal some grain. I then sprayed a clearcoat to keep it from rusting and that was it.
The top of the desk is a greenish frosted glass, and now the bare metal looks like brushed aluminum. Beautiful!