Hi there!
I´m already working on my free time on a optimized mesh with less than 2k vertices (same UV), I´ll probably be able to provide it next week.
If you still want to use yours, I recommend it to match the same volume of base meshes, to keep clothes working for you. You need rig it using UMA base mesh bones and ideally project the skinning data, to avoid a huge work of skinning from scratch.