Building a level 21 Sorcerer in 4e DnD

[theonesin]

So, in our campaign our characters have ended up jumping from level 12 to level 21 (from here on though, we're leveling at a normal pace), and the DM wants us to pretty much rebuild our characters from scratch, losing most of our items (except a custom item the DM gave each of us. Mine happens to give me constant consealment), but keeping our gold.

For reference, this is my character at level 12:

Level 12
Changeling, Sorcerer, Daggermaster
Spell Source: Wild Magic
Background: Akanûl

FINAL ABILITY SCORES
Str 11, Con 14, Dex 21, Int 11, Wis 10, Cha 21.

STARTING ABILITY SCORES
Str 10, Con 13, Dex 16, Int 10, Wis 9, Cha 16.


AC: 25 Fort: 20 Reflex: 23 Will: 27
HP: 81 Surges: 8 Surge Value: 20

TRAINED SKILLS
Arcana +11, Intimidate +16, Diplomacy +16, Bluff +18, Thievery +16

UNTRAINED SKILLS
Acrobatics +11, Dungeoneering +6, Endurance +10, Heal +6, History +6, Insight +8, Nature +6, Perception +6, Religion +6, Stealth +11, Streetwise +11, Athletics +6

FEATS
Level 1: Dual Implement Spellcaster
Level 2: Focused Expertise (Dagger)
Level 4: Weapon Focus (Light Blade)
Level 6: Armor Proficiency (Leather)
Level 8: Sneak of Shadows
Level 10: White Lotus Riposte
Level 11: War Wizardry
Level 12: White Lotus Master Riposte

POWERS
Sorcerer at-will 1: Acid Orb (retrained to Burning Spray at Level 7)
Sorcerer at-will 1: Chaos Bolt
Sorcerer encounter 1: Mists of Disarray
Sorcerer daily 1: Ice Javelins
Sorcerer utility 2: Focused Chaos
Sorcerer encounter 3: Ice Dragon's Teeth
Sorcerer daily 5: Thunder Leap
Sorcerer utility 6: Sudden Scales
Sorcerer encounter 7: Spark Form
Sorcerer daily 9: Contagious Curse
Sorcerer utility 10: Fate's Chaos (retrained to Narrow Escape at Level 12)

ITEMS
Siberys Shard of the Mage (heroic tier) (2), Adventurer's Kit, Grappling Hook, Cloak of Survival +2, Deathcut Leather Armor +2, Bloodiron Dagger +3, Boots of Eagerness (heroic tier), Salve of Power (heroic tier), Staff of Ruin +2, Shadowfell Gloves (heroic tier), Circlet of Mental Onslaught (paragon tier), Ruby Scabbard (heroic tier)


Basically, I'm looking for any advice on changes I should make on this character for what he has now, and where to take him from there (I'm really not sure what Epic Destiny to take). We can't change our race and current Class/Paragon Path (not that I want to anyway).

For our items, we get:

1 item our level +1
1 item our level
1 item our level -1
Money equal to a level 20 item, plus the 2,832GP I have left.

Any help would be great. Thanks.