I recommend having busts of your designs commissioned first, then have someone sprite up the character sets to match the bust and face materials flawlessly. You may not be having busts done, but I'd still have the faces finished first.
Dig around old ReStaffs and project-friendly resources for hats and other sprite apparel you can add to your generator library, or edit to suit your needs.
I am decent with RPT edits, but not much beyond that, unless you are wiling to use Loose Leaf sprites. If LLs are on the table, contact me to see some example work at no cost or obligation (I love making LL sprites, and care little about credit, only people's projects).