I can highly recommend those Carlo Spirito figures. Bought a few sets fom the late Steve Warrington and directly from Carlo.
Since they come with seperate heads, you can always mount heads from other makers, e.G. from the Preiser trackworkers.
The kit contains a few spares.
The masters plus rights should be aquired by someone with experience with mould making and resin casting. Thinking of Steve Bennett, but he seems not to be around in this forum anymore.