Hey guys,
I took some time and investigated the 'horse model issue' and finally I 
think to know what's going on.
First it was a bit confusing to understand how this works, how the model is determined, where the specific horse shapes come from.
With the help of a local DOL server, the client data (mpk files) and analyzing the DOL DB I figured out following details:
- All mount horses have the model 2912
- The specific type of a mount horse is stored in the column 'SPD_ABS' in the table itemtemplate
- To match the numeric value from the SPD_ABS column to the actual horse model take a look at the horsemap.csv in the gamedata.mpk of the game client
Within the horsemap.csv there exists generally 3 different types of horses, described as 'Standard', 'Heavy' and 'Unicorn' (with the exception of the Epic horses and the Nightmare, Undead and Sea Horse) so they use a unique pattern of
Name [Standard|Heavy|Unicorn]
Within the DOL DB the naming is a bit different.
There are Heavy Mounts, Standard Mounts, War Mounts and even just Mounts (so no Unicorn mentioned).
One would expect that the ones called just 'xxx Mount' that these are the unicorn versions.
This is also true for some types, e.g. the in a previous post already mentioned Palomino.
The item you can buy by from Krigih is called 'Palomino Mount' for 200g and in fact this is a unicorn shaped mount.
However, e.g. for the item Chocolate Mount, it's the Chocolate Standard, the Leopard Mount is the Leopard Heavy.
So in my opinion 
1.) the naming of the mounts is not clear
2.) the matching between mounts which are simply called 'xyz Mount' is inconsistent (sometimes it's a standard, sometimes a heavy and sometimes a unicorn)
Additionally there are some more mounts available than sold by Krigih (but okay, that's not necessarily an issue 

 )
I would suggest to rename the Mounts sold by Krigih in a consistent way, like Name + Standard/Heavy/War/Unicorn and correct also the matching to the right looks.
Let me know if you have any questions about that or if I can help somehow to correct that 
Cheers
Preachie