Gavroche has really sensitive skin and the only collar I've found that works for him so far is his EL leather lined in suede. I got him a satin-lined Collar Mania ribbon collar and it was awful on his neck - it was sewn with some sort of fishing line type thread (?) and the pokey bits tore him up pretty good.
I have yet to find ribbon collars that I really like - they all seem to have a nylon base, which is pretty harsh. Maybe a fabric collar would work well? Still no help there because I don't know of any fabric collars I really like either lol, mostly because I stopped looking.
How about braided kangaroo? I think Braid-a-Roo charges around $1.50 per inch, so wouldn't be too bad for his size. That's for a tag collar that slips over the head, not sure what options they have for regular collars.