Cute, I had a hard time choosing between blue and silver. I like to wear grey more though, so I got silver. I'm looking at blue fabrics with cat prints for a lining.
I've found 30+ pieces of official merch in the last week that fit my criteria of "happy and/or human Alphonse, but no CoS" not including a couple additional Xiao Mei and Mei Chang pieces, pie charms, flowers, and cat charms. Japanese secondhand sites, vague keywords, and patience are the way to go. There's an Alphonse shaped phone charger out there if you look hard enough.
Two other interesting things I found are official pre-inked stamps of his :3 face that I plan to use for custom buttons. If I have any space whatsoever left, I'm going to make large badges from the final chapter, there's several lovely panels of him in it, and coloring them specifically with my bag in mind could tie the whole thing together palette wise.