Polearm Momentum says "Whenever you use a polearm or a spear attack to to push or slide a target 2 or more squares..."
... which a Fighter can't do until he goes Polearm Master (which adds 1 to every forced movement he makes with a polearm). So Polearm Momentum needs only be taken at 10th or retrained into at 11th.
Here's what I have so far:
Brunhild, level 11
Eladrin, Fighter, Polearm Master
Fighter Talents: Two-handed Weapon Talent
Background: Arcane Sentinel (Arcana class skill)
FINAL ABILITY SCORES
Str 20, Con 11, Dex 17, Int 11, Wis 16, Cha 12.
STARTING ABILITY SCORES
Str 17, Con 10, Dex 13, Int 8, Wis 15, Cha 10.
AC: 24 Fort: 22 Reflex: 18 Will: 19
HP: 86 Surges: 9 Surge Value: 21
TRAINED SKILLS
Heal +13, Endurance +10, Arcana +12, Athletics +15
UNTRAINED SKILLS
Acrobatics +8, Bluff +6, Diplomacy +6, Dungeoneering +8, History +7, Insight +8, Intimidate +6, Nature +8, Perception +8, Religion +5, Stealth +8, Streetwise +6, Thievery +8
FEATS
Level 1: Eladrin Soldier (+2 damage with spears, greatspear prof)
Level 2: Exotic Fighting Style (when using Sure Strike, add prof bonus to damage)
Level 4: Weapon Expertise (Spear)
Level 6: Ritual Caster
Level 8: Moon Elf Resilience (if no allies within 5 square and fey step when bloodied, spend surge)
Level 10: Polearm Momentum
Level 11: Fey Charge (reliable fey step when charging)
POWERS
Fighter at-will 1: Reaping Strike
Fighter at-will 1: Sure Strike
Fighter encounter 1: Lunging Strike (+1 reach)
Fighter daily 1: Brute Strike
Fighter utility 2: Pass Forward (at will)
Fighter encounter 3: Armor-Piercing Thrust
Fighter daily 5: Nimble Bladestorm
Fighter utility 6: Defensive Training
Fighter encounter 7: Trip Up
Fighter daily 9: Shift the Battlefield
Fighter utility 10: Into the Fray
ITEMS
Eladrin Finemail +2 (+1 square to all teleports), Greatspear of Myrdroon's Shard +2 (make basic attack with +1 reach and lightning damage at will), Bracers of Escape (heroic tier) (teleport when grab/restrain/immob, stacks with Eladrin Finemail)