My Spines/EA PVP stalker is doing pretty well for himself, I sacrificed defence for pool powers (4 of them at lvl 26) and have no regrets, hes a stalker not a scrapper and thats how I play him.
**Acceptable "support" responses**
Its your fault
Its your computers fault
Its your ISPs fault
Ok, i'm sold on the no defences way, all i'm going to take initially is Entropy Aura to stop me being nailed by status effects.
Any opinions on whether stamina is worthwhile? I understand that due to the sporadic bursts of fighting in PvP it's not really worthwhile, although I can see the uses of 3 slotted health to top up my green bar as I run and hide.
You've certainly come up with a unique way to play a stalker and i have to say i like it alot.
Yeah you probably gotta take stealth really if your going pure PvP. Without it anyone with a bit of perception wont be fooled.
The build looks great so far. Take hover soon so u can get those pesky flying blaster. (Tp up to them and AS). Then later you can take fly as well if you want.
Good luck and happy hunting 
I'm now on my third attempt at doing a stalker, and I'm having a bit of difficulty I'd like to focus mainly on a PvP build but need to have the ability to level ok to get there.
So far this is what I think I'm going to head towards, I'm level 8 at the moment so hopefully theres plenty of time to correct any mistakes I have made.
---------------------------------------------
Exported from Ver: 1.6.8.0 of the CoH_CoV Character Builder - (http://home.comcast.net/~SherkSilver/index.html)
---------------------------------------------
Name: Grotesque
Level: 17
Archetype: Stalker
Primary: Energy Melee
Secondary: Energy Aura
---------------------------------------------
01) --> Energy Punch==> Dmg(1)
01) --> Hide==> EndRdx(1)
02) --> Bone Smasher==> Acc(2) Acc(3) Dmg(3) Dmg(5) Dmg(5)
04) --> Barrage==> Dmg(4)
06) --> Assassin's Strike==> Acc(6) Acc(7) Acc(7) Dmg(9) Dmg(9) Dmg(11)
08) --> Build Up==> Rechg(8) Rechg(11) Rechg(13)
10) --> Teleport Foe==> Empty(10)
12) --> Placate==> Rechg(12) Rechg(13) Rechg(15)
14) --> Teleport==> EndRdx(14) EndRdx(15)
16) --> Entropy Shield==> EndRdx(16)
---------------------------------------------
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Assassination==> Empty(1)
02) --> Rest==> Empty(2)
---------------------------------------------
At this point i'm a little lost as I understand Stealth is required for PvP and a secondry movement power is also useful but I would normally get the fitness tree past this point. I have been asking other stalkers that I meet and many say that getting at least some defence is required but I have never found it to be that useful especially the higher I get in level.
Any help would be appreciated.