Got mine to 27 so far, haven't bothered with the fitness pool, hit and run tactics used, and been very useful so far.
I would take Assassin Strike at 6, Build-Up at 8 and also slot recharges in this power first, wouldn't worry too much about slotting you defences early on, they only really benefit properly slotted with SO's, but extra damage could help you a lot more.
I would also slot accuracy in first two slots, then the 3 damage slots to help maximise your endurance expenditure.
Boxing and Tough are really not worth taking, as unlike Energy Aura on a brute the Res from Tough has nothing to stack with.
Would Probably take Combat Jumping and Super Jump rather than Air Sup and Fly, CJ gives you a nice Def boost almost for free as well as improving your vertical movement.
This means you can take lots of "other" powers to benefit your short sharp shock tactics.
I know your for PvE, so unlike mine who's got Stealth and Grant Invisibility for PvP, you could take Aid Other and Aid Self.
At lvl 20 i took Power Shield, Lvl 22 Barrage, Lvl 24 Grant Invis, Lvl 26 Energy Transfer, and I love this one even though it can hurt me. Lvl 28 I can get Energy Drain, leaving Hasten for lvl 30, which will help all of the other powrers cycle faster. Total Focus obviously at 32, conserve power at 35 as I don't have stamina and may be doing some minor scapper duties in party's and of Course Overload at 38.
I'm going for Mace mastery as my PPP, mainly due to being a technology type background.
Hope this helps, and have fun.
Thanks 
Hi,
I am building a PVE only build and will be starting him from scratch.
The main aim of my build is to do a very survivable assasin, can you please take a look.
Thanks.
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Exported from Ver: 1.7.6.0 of the CoH_CoV Character Builder - (http://sherksilver.coldfront.net/index.php)
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Name: Name Sinnerman
Level: 44
Archetype: Stalker
Primary: Energy Melee
Secondary: Energy Aura
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01) --> Energy Punch==> Dmg(1) Acc(3) Dmg(7) Dmg(25) Acc(43)
01) --> Hide==> EndRdx(1)
02) --> Bone Smasher==> Dmg(2) Acc(3) Dmg(7) Dmg(25) Acc(42)
04) --> Kinetic Shield==> DefBuf(4) DefBuf(5) DefBuf(5) EndRdx(37)
06) --> Swift==> Run(6)
08) --> Assassin's Strike==> Dmg(8) Acc(9) Acc(9) Dmg(11) Dmg(11) Rechg(37)
10) --> Air Superiority==> Acc(10) Acc(17)
12) --> Placate==> Rechg(12) Rechg(13) Rechg(13)
14) --> Fly==> EndRdx(14) EndRdx(15) Fly(15)
16) --> Entropy Shield==> EndRdx(16) EndRdx(17)
18) --> Health==> Heal(18) Heal(19) Heal(19)
20) --> Stamina==> EndMod(20) EndMod(21) EndMod(21)
22) --> Build Up==> TH_Buf(22) TH_Buf(23) TH_Buf(23) Rechg(43) Rechg(43)
24) --> Boxing==> Acc(24)
26) --> Tough==> DmgRes(26) EndRdx(27) DmgRes(27) EndRdx(37) DmgRes(40)
28) --> Energy Transfer==> Dmg(28) Acc(29) Dmg(29) Dmg(34) Acc(34)
30) --> Energy Drain==> Rechg(30) EndMod(31) EndMod(31) EndMod(31)
32) --> Total Focus==> Dmg(32) Acc(33) Dmg(33) Dmg(33) Acc(34)
35) --> Power Shield==> DefBuf(35) DefBuf(36) DefBuf(36) EndRdx(36)
38) --> Overload==> Rechg(38) Rechg(39) Rechg(39) Heal(39) DefBuf(40) Heal(40)
41) --> Energy Protection==> DmgRes(41) DmgRes(42) DmgRes(42)
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01) --> Sprint==> Speed(1)
01) --> Brawl==> Empty(1)
01) --> Assassination==> Empty(1)
02) --> Rest==> Rchrg(2)
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