Wiredkiwi sends us some additional info on the horses used for the films:

A grey Andalusian stallion named Florian was used for close up and stunt work, and his (now) owner was the riding double for Liv Tyler. Florian now gives displays at equestrian events around NZ and is standing at stud.

Strider’s horse in the film is a very high profile stallion in NZ, being one of the top dressage horses in the country, owned, trained and ridden by Bill Noble. Can’t remember the name of the horse for the life of me though. Rumor has it that Viggio Mortensen, who was the most enthused about horses of the ‘fellowship’ liked him so much he tried to by him after filming. However this was not the bay Andalusian offered for sale.

NZ Horse and Pony maazine would possibly be able to supply you with the full copy and perhaps images of the feature they did on the LOTR horses.