A few ways to go:
1. Become a paladin. I presume this is not a desirable way to go for you.
2. Create a new prestige class, using the paladin's mount as a guide for mount advancement. You'd need to be very mount-oriented, perhaps requiring the mounted combat feats and lots of ranks in riding - if we are talking a special mount, then animal handling won't be required or of any value, since your mount would be a magical beast, not an animal.
3. Create a new prestige class that gets you a special mount which has intelligence of at least 4 or so and advances as a magical beast in a way that's similiar to a cohort - let it have 1/2 your experience points for advancement, but with no impact to party experience point awards. This pseudo-leadership feat would be a class feature. If you leave the mount with no other powers, it might be reasonable to NOT require a year-and-a-day delay before you could get a new one, if it is killed. This is pretty much new rules territory, but that's partly what prestige classes are for.
Of course, you'd need to work out why this prestige class exists and how they get their special mounts - quest, gift, automagically, etc.
Whichever way you go way, consider a Celestial War Dog with Celestial Armor for your mount, if you are a halfling. Very cool, very useful even indoors.
Also, here's something handy to have in your hip pocket:
If you read all the WotC supplemental materials, it appears that normal animals get only one magical item allowed (IIRC - from MotW - I think you'd normally stretch it to two when including barding), whereas familairs (and other magical beast companions, one assumes, like special mounts) get mutiple slots like anyone else - this is from T&B.