https://classicdb.ch/?talent#hxcZxifzExut
Here i focus on defense, with 10% elem reduction +5% dodge and 10% armor and i have stormstrike :)

https://classicdb.ch/?talent#hZxVfzV0uxxfct0oo
Here i forget defense and go survivability, with 70% of non interuption while casting and the insta cast, always good. ( the best choice for pve solo)

https://classicdb.ch/?talent#hgc0xf0oZxVfzV0ux
Here i go full dmg, with elemental fury and the 1 sec cd on shock

Wich one is the best for pvp in your opinion ?
Does the insta cast heal of the second build overpower the defensive prowess of the first build ?
Does the extra dammage of the 3rd build owerpower the stormstrike of the 1st build for burst capacity ?

Please give me your ideas and views on shaman builds in pvp.

Pretty sure Shaman plays like a Balance/Resto druid in terms of PvP - Ele/Resto

Afaik in bgs/pvp you just spam LB and rank 1 shocks for CC, purging what you need to purge, healing what you need to heal and totem in the needed scenario.

Specs
If you do have mana problems
If you do not have mana problems

Shamans are a really good group player, rather than a 1vs1 class. However, there was a rather quirky 1vs1 specialization that focused on Elemental tree but still went 2H talent in Enhancement just for the Windfury. It sort of take people offguard when you're off casting chain lightning with big crits to then suddenly pull off windfury crits when people get in your melee range.

If you're playing Enhancement, I'd go something like this:
https://classicdb.ch/?talent#hZxVbzExutx0e

If you're playing Elemental, I'd go something like this:
https://classicdb.ch/?talent#hE0zAcMqoZxoez0x

If you're playing a more hybrid Enh/Ele spec, I'd go something like this:
https://classicdb.ch/?talent#hxfzVzhZxV0zE0ut

I never got a Shaman to 60 during Vanilla, but I did PvP with one up through the 40's. I LOVED playing Enhancement Shaman. A lot of it was RNG, hoping to get your windfury procs for big bursts of damage, but when you did... man, it was the best feeling.

To be fair though, when you didn't get the procs, you sometimes felt like a wet noodle. I still liked it, but I'm just a sucker for that kind of play.

I can't really comment on talent specs that much since it's been so long since I played and I pretty much only went for the WF oneshot build.