Just an idea---- readily avalible at most parts stores and Wal-Mart is the Duplicolor brand of automotive laquers by Sherwin Williams. This can give you more color options as well as some of the metallics are large enough to simulate metal flake when used on a model.
I have used it on several models including my latest, AMT's 69 Olds 442.
Just like any other laquer though, it takes some work after it's dry. I take 2000 grit wet-or-dry and color sand after 24 hours, and then either use Model-Master high gloss clear, OR simply polish with 3M's Imperial hand glaze. This makes it look like a sheet of glass!
Check them out at www.dupli-color.com