Level 1 (Duskblade): Still Spell
Level 1 (Duskblade): Power Attack
Level 3 (Duskblade): Combat Reflexes
Level 4 (Fighter): Weapon Focus [Glaive]
Level 5 (Fighter): Short Haft
Level 6 (Duskblade): Repeat Spell
Level 9 (Duskblade): Arcane Strike or Extra Spell: Wraithstrike
Level 12 (Duskblade): Arcane Strike or Extra Spell: Wraithstrike
The only reason I pick Still Spell at level 1 is because I need a metamagic Feat to get Repeat Spell (which I want to use for True Strike). Or is the Repeat Spell not all that good? I’m also considering switching the first two Feats to a Crusader Maneuver and Stance (Martial Spirit) so I can heal myself a little bit in a party that lacks a good healer.
Since there are three tanks already, I want to opt for a supporting role. Using a reach weapon (glaive) with Combat Reflexes will give me enough opportunities to make Attacks of Opportunity and the reach of the glaive will make it easier for me to use Arcane Channelling.
1) Depending upon your DM's interpretation, Extra Spell doesn't allow you to add spells from other class lists. You may want to check. If it does, also consider the spell Whirling Blade, which (again, depending upon interpretation) is a candidate for Sculpt Spell.
2) Short haft sounds great, but IME you're better off just using Armor Spikes (or IUC, if you have it).
3) Still Spell is not the best choice for this PC since he can already cast in Armor to a certain point. You'd be better off with something like Silent Spell, Extend Spell, Reach Spell, Sculpt Spell, or some such.
4) Combat Reflexes is your friend. To get the most out of it, you should probably take Deft Opportunist to get +4 to each of your AoOs.
5) I want to like True Strike, I really do- its one reason I'm currently playing a multiclassed Diviner. However, IME, the spell is usually wasted- it takes a Standard Action to cast, and by the time I get it off, the party tanks have eliminated any target within my striking range. Its a spell that is probably best partnered with Quicken Spell or used by archers or ray specialists.