After killing a whole lot of orcs, collecting their medallions and turning them in to the Rangers of Esteldin, the rangers will eventually consider you one of their own and bestow you with the title of Honorary Ranger. Just like with most other factions you may then purchase a horse from them. The Esteldín Horse is also for sale in the lotro store. The store horse will have slightly less morale, but it will save you the trouble of grinding for the reputation. It is a lovely palomino horse that is certainly worthy of carrying a friend of the Rangers.
The cloak in this outfit requires kindred status with the Ale Association, a band of drunk dwarves that are only around during seasonal festivals.
Head: Plumed Hat, rust dye (introduction instance quest, light)
Chest: Jacket of the Heartmender, umber dye (Evendim barter tokens, minstrel only)
Shoulders: Padded Cloth Shoulder Pads, umber dye (light armour smith)
Hands: West-land Gloves, umber dye (crafted, heavy)
Legs: Westernesse Radiant Leggings, olive dye (crafted, light)
Feet: Glossy Leather Boots, umber dye (outfitter, cosmetic)
Back: Cloak of the Ale Association, olive dye (AA kindred reputation, cosmetic)
Horse: Prized Esteldín Horse (Esteldín kindred reputation)
Cosmetic Lotro 
I can’t seem to find reference to a “Jacket of the Heartmender in any LOTRO item database–I see shoes, and pauldrons, but no jacket. Has this item been removed from the game?
It is available from the barter in Tinnundir. The one standing at the bottom of the stairs to the keep. You need Arnorian coins to buy it.