You don't need your own horse. As soon as you land, you will see a horse and you can choose the kind of horse you want or the kind that will not get your avatar's legs into their belly. I tried a few until I got to Jigsaw. I think it's an Arabian. It's width is quite slim and my legs didn't get 'eaten'.
Hair: TRUTH Montana - Blonde
Skin: MUDSKIN_JENNIE # SASEUM
Eyebrows: Nuve Crystal Eyebrows
Eyes: Tville Charming Eyes Olive
Cosmetics: *Heron Denise
Body: Maitreya Lara
Top: Decoy - Maya Crop Top: Leaf2 Red
Jeans: Blueberry - Evie - High Waist Jeans - TSS 10/16 - Light Pack
Boots: -KC- WANDA BOOTS
Shape: 1L on My Marketplace.