Basically what I'm looking for is a mod that adds more horse armor (not replaces the originals). Preferably horse armor that uses the same stats as the originals, just cosmetically different.

I use Slof's Horses Base, Better Horse Eyes and Zira's Horse Compilation. So nothing it can't conflict with them either.

I've seen this mod but I see lots of people complaining in the comments about how it doesn't work in many ways. It also has a quest packed with it which I'd prefer to forgo for just extra armor options.
http://planetelderscrolls.gamespy.com/View.php?view=OblivionMods.Detail&id=3501

Problem is there are not many that change the armor due to the fact that it is a DLC and you can not include the original Nifs in a mod package (otherwise those users that did not pay for the DLC would have access to the armor ) So most of them are simple retextures that swap out the new textures for the old (so that it can be done without distributing the NIF files -- There were a few new Armor models being worked on awhile back that were new models so the Nifs could be distributed but not sure if any public release was ever completed (http://i212.photobucket.com/albums/cc189/JDFanning_bucket/Oblivion2009-01-2616-57-07-68.jpg ) The NIfs were made by Mr. Siika IIRC and were given to someone else to create a release but a lot of time had gone by with no release so I lost track of the mod and am not sure if the models were ever actually used in a mod or not. (you might try contacting him to see if they were or are aviailable for use anywhere.)

I don't know if they are the same meshes or not but Mr Siika included some with castle Seaview which Zira has used in some of his/her mods.

Thanks guys. Bumping to say thanks, but if anyone has any more contributions feel free to post