Help building my first (second) character!

[Dhoule]

Ok, so... summing up:

Lvl: 6
Race: Human
Alignement: CG/NG
Class: Duskblade


ABILITY SCORES
STR 17
DEX 10
CON 14
INT 14
WIS 8
CHA 8

FEATS
Must have: Power Attack (PHBI), Arcane Strike (CW)
Should consider:
- Spell Penetration (PHBI), Exotic Weapon Proficiency: Spiked Chain (PHBI), Combat Expertise (PHBI), Improved Trip (PHBI), Toughness (PHBI)
- Steadfast Determination (PHBII)
- Mobile Spellcasting (CAd), Leap Attack (CAd)
- Obtain Familiar (CAr), Energy Substitution: Acid (CAr), Precocious Apprentice: Heroics/Burning Sword (CAr)
- Spellcasting Prodigy (PGtF, must be level 1), Luck of Heroes (PGtF, must be level 1), Mercantile Background (PGtF, must be level 1, don't know if my DM will allow it)
- Arcane Disciple? (I really like this one, though with low Wisdom it'd be pointless) (CD)
- Improved Toughness (CW), Close Quarters Fighting (CW), Improved Familiar (CW)
I'd like to but can't have: Knowledge Devotion (CC)

Which 4 would you choose for level 6?

SKILLS
Concentration
Jump? (Leap Attack?)
Knowledge (?) (no Knowledge Devotion, remember)
Listen?
Sense Motive? (it's a class skill, and I like it for role playing)
Spellcraft?
Spot?
Tumble?

EQUIPMENT
Armor: Breastplate (+1, if I can afford it, as Mithral Full Plate Armor won't be possible for now)
Shield: Buckler? Light Shield? Heavy Shield? None?
Weapon: Greatsword? Longsword? Glaive? Guisarme? Spiked chain?
Items: ?

Anything else?