I would post my sonic/em build but i had to reinstall windows on my PC and lost all my builds. I will try make something up to help you out.
"You wrote that the world doesn't need a saviour, but everyday I hear people cry for one"
Mortilance - Elec/WP Stalker
Wasn't sure of your budget so i made a fairly cheap build. Obviously you can switch the IO's in the attacks for purples (Apocs, Amazements and Heca's) but as they are pretty expensive atm i didn't include them. See what you think 
Hero Plan by Mids' Hero Designer 1.601
http://www.cohplanner.com/
Click this DataLink to open the build!
Level 50 Magic Blaster
Primary Power Set: Sonic Attack
Secondary Power Set: Energy Manipulation
Power Pool: Fitness
Power Pool: Leaping
Power Pool: Speed
Power Pool: Leadership
Ancillary Pool: Cold Mastery
Hero Profile:
Level 1: Scream -- Dev'n-Acc/Dmg(A), Dev'n-Dmg/Rchg(3), Dev'n-Acc/Dmg/Rchg(7), Dev'n-Acc/Dmg/EndRdx/Rchg(7), HO:Nucle(17), Range-I(23)
Level 1: Power Thrust -- KinCrsh-Dmg/KB(A), KinCrsh-Acc/KB(42), KinCrsh-Acc/Dmg/KB(43), KinCrsh-Dmg/EndRdx/KB(43), HO:Nucle(43)
Level 2: Shriek -- Dev'n-Acc/Dmg(A), Dev'n-Dmg/Rchg(3), Dev'n-Acc/Dmg/Rchg(5), Dev'n-Acc/Dmg/EndRdx/Rchg(5), HO:Nucle(17), Range-I(23)
Level 4: Build Up -- AdjTgt-ToHit(A), AdjTgt-ToHit/Rchg(13), AdjTgt-ToHit/EndRdx/Rchg(15), AdjTgt-EndRdx/Rchg(31), AdjTgt-Rchg(36)
Level 6: Hurdle -- Jump-I(A), Jump-I(50)
Level 8: Shout -- Dev'n-Acc/Dmg(A), Dev'n-Dmg/Rchg(9), Dev'n-Acc/Dmg/Rchg(9), Dev'n-Acc/Dmg/EndRdx/Rchg(11), HO:Nucle(11), Range-I(25)
Level 10: Combat Jumping -- LkGmblr-Rchg+(A), Krma-ResKB(34), Ksmt-ToHit+(34), Zephyr-ResKB(37)
Level 12: Amplify -- AdjTgt-ToHit(A), AdjTgt-ToHit/Rchg(13), AdjTgt-ToHit/EndRdx/Rchg(15), AdjTgt-EndRdx/Rchg(31), AdjTgt-Rchg(36)
Level 14: Super Jump -- HO:Micro(A), Zephyr-ResKB(46)
Level 16: Health -- Numna-Regen/Rcvry+(A), Mrcl-Rcvry+(31)
Level 18: Hasten -- RechRdx-I(A), RechRdx-I(19), RechRdx-I(19)
Level 20: Stamina -- P'Shift-EndMod(A), P'Shift-EndMod/Rchg(21), P'Shift-EndMod/Acc/Rchg(21), P'Shift-EndMod/Acc(36), P'Shift-End%(37)
Level 22: Acrobatics -- EndRdx-I(A)
Level 24: Maneuvers -- LkGmblr-Rchg+(A), Krma-ResKB(25)
Level 26: Screech -- Stpfy-Acc/Rchg(A), Stpfy-EndRdx/Stun(27), Stpfy-Acc/EndRdx(27), Stpfy-Stun/Rng(29), Stpfy-Acc/Stun/Rchg(29), HO:Endo(37)
Level 28: Power Boost -- RechRdx-I(A)
Level 30: Super Speed -- HO:Micro(A), HO:Micro(40), Zephyr-ResKB(42), Winter-ResSlow(42)
Level 32: Tactics -- AdjTgt-ToHit(A), AdjTgt-ToHit/Rchg(33), AdjTgt-ToHit/EndRdx/Rchg(33), AdjTgt-EndRdx/Rchg(33), AdjTgt-ToHit/EndRdx(34)
Level 35: Boost Range -- RechRdx-I(A)
Level 38: Total Focus -- Mako-Acc/Dmg(A), Mako-Dmg/Rchg(39), Mako-Acc/Dmg/EndRdx/Rchg(39), Mako-Dam%(39), HO:Nucle(40), Rope-Acc/Stun/Rchg(40)
Level 41: Snow Storm -- EndRdx-I(A)
Level 44: Hoarfrost -- S'fstPrt-ResKB(A), Mrcl-Heal(45), Mrcl-Heal/EndRdx/Rchg(45), Mrcl-Heal/Rchg(45), Dct'dW-Heal/Rchg(46), Dct'dW-Rchg(46)
Level 47: Frozen Armor -- LkGmblr-Rchg+(A), LkGmblr-Def/EndRdx(48), LkGmblr-Def/EndRdx/Rchg(48), LkGmblr-Def(48), Krma-ResKB(50), S'fstPrt-ResKB(50)
Level 49: Hibernate -- RechRdx-I(A)
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Level 1: Brawl -- Empty(A)
Level 1: Sprint -- Empty(A)
Level 2: Rest -- Empty(A)
Level 1: Defiance
"You wrote that the world doesn't need a saviour, but everyday I hear people cry for one"
Mortilance - Elec/WP Stalker
I have a level 50 Sonic/Em Blaster. I PvPed with him for awhile, but couldn't stand the animation time. So...with that said. I was gaining interest in using him again. Anyone have a pretty solid build?
PvP IOs will be limited if possible. The market is totally borked right now.