Source for AC grills

[Pete]

The master stateroom and pilot house AC ducts and grills are located on the overhead. The output grill on each is one of those three direction curved louvers type which I consider useless. So I am looking to replace all four brown/bronze colored grills with new white units (matching the headliner) that have the standard adjustable two level louvers on the supply grills and single level fixed louvers on the return grills. Have checked Sam's catalog and see nothing close to what I need. Does anyone know of a source for custom size replacement AC grills, either in white powder coat aluminum or PVC frames that have the same shape as the original aluminum versions, but missing the condensate dripping option? Thanks.

Pete