While agi is nerfed these days, I'd still suggest 18-18. That way your build can be this:
Level 30 (4 420 577 xp)
Strength: 18
Agility: 18
Hit points: 63
Skills to attributes: 2
Ironflesh: 5
Power Strike: 6
Shield: 6
Athletics: 6
Riding: 0
Horse Archery: 0
Power Draw: 0
Power Throw: 0
Weapon Master: 6
One Handed: 100
Two Handed: 1
Polearm: 135
Archery: 1
Crossbow: 1
Throwing: 1
More shield skill will help your shield to keep up, the little more moving speed makes your role as a support better.
Weapons, well, I'd suggest Ashwood Pike as your spear. Hands down the very best hoplite weapon. If you prefer to be alone, then maybe Double Sided Lance for being fast, and having a nice stab dmg, still.
For your sidearm, I'd suggest a a blunt weapon, like Iberian Mace.
Shield, well, choose one which only takes one slot, like all the Cavalry shields, Board Shield (normal Board), or Heavy Round Shield. I'd say take a Heavy round shield.
Tips for battle:
1) Stay with someone. That way you can stab the enemy when he's trying to attack your friend, so you can easily gang him.
2) Use your shield. Sometimes you need to just block, like when defending archers or a chokepoint.
3) 1handed spear is VERY good for stabbing behind cover, like in siege. Just stand where the ladder is, stab enemies while your face is protected by the walls.
4) Remember where you drop your spear when you have to drop it.
5) Learn the right time to stab, and how to turn your stabs for better hits.