Paladin Bullette Mount

[Lanson]

Hey, I was looking through my RoS book recently, and saw that bullettes are a viable mount for dwarven characters. Is there any way I could make one a Paladins special mount WITHOUT needing to homebrew anything? Or would I have to just purchase the mount and forego my normal mount?

[Stux]

The standard mount for a Medium paladin is a heavy warhorse, and the standard mount for a Small paladin is a warpony. Another kind of mount, such as a riding dog (for a halfling paladin) or a Large shark (for a paladin in an aquatic campaign) may be allowed as well.

The bolded 'may' makes it pretty clear to me that anything other than a heavy warhorse for medium or warpony for small must have DM approval.

[Lanson]

Looks like by the DMG rulings, I could obtain an unusual mount bulette at paladin level nine... however, we all know paladin 9 is too many paladin levels. I think I'll just convert to a supermount build and eat the penalties of having an unusual mount for some extra awesomesauce.

Someone, please correct me if I'm wrong. I would like this to be a legal build.