No specific answers but some thoughts.
The Copplestone figures are very nice, and are at the slighter end of 10mm size wise.
Pendraken historical figures will fit well, their dark ages and medieval ranges should provide good figures. Pendraken fantasy figures are rather large, they could be called 12mm, so not a good source of Dwarfs or Hobbits as they are bigger than the humans! Norman cavalry might work for Gondor? Or the late roman figures?
MM have nice figures, they are similar height wise to CS, but are bulkier. MM cavalry have quite small horses to may match well to CS.
TB line – nice figures, very detailed. Infantry should match up well, not certain about cav which have quite large horses.
GW Warmaster – probably the best source for Dwarfs and Elves, can often be found on eBay for much less than GW retail. Not the clearest picture but the Elf Archers have the look of the film, I think
GW Battle of Five Armies – now unfortunately OOP had lots of plastic figures there were some metal figures produced but these are very hard to get hold of. I have a hope (probably in vain) that the upcoming Hobbit movie might revive this line :-(
The plastic elves
and dwarfs