Madmod... I have attached a couple of links for material to look at, see if they can help you. Honestly I run stainless steel mesh on mine. No worries about pitting, no maintenance and no worries about oxides building up on them. Hope this helps some.
Cheers!
The first link will get you to a Titanium expanded mesh company:
expanded metal,Titanium Expanded Metal-Anping Qinghe expanded metal factory
This has aluminum, stainless and titanium
Flattened Expanded Metal, Stainless Steel Expanded Metal, Expanded Aluminum, Cold Rolled Metal