One of the last Crimean projects I did was almost wargaming it. I was going to wargame it in 15mm with Dave Allen being the Russians and myself being the French. The figures we were going to use were Minifigs which I can't vouch for on the Russian and British side but for the French they weren't that impressive - I got as far as line infantry and Spahis - Dave had already bought his large Russian army but couldn't get round to painting it so we stalled. Then I got very enthusiastic about the Emhar 1/72 Crimean figures - they don't do a full range but their French infantry and Zouaves were good with separate backpacks which look good assembled, and I actually painted and based a few of them. The rules we were going to use were the ACW set Fire and Fury Fire and Furia Francese with the Crimean modifications as found on this page.
Now I suppose I want something that doesn't exist 40mm or 54mm figures maybe - I'll be looking around to see if anything's out there that appeals to me - let me know if there's anything good that I might miss.
If you want to see what metal miniatures might work for the Crimean War in 1/72 the Plastic Pelisse has some great comparisons.