What is the BEST Shield for a Ret Paladin in PvP

The title says it all:

I am trying to find out what is the best shield for a paladin to use in PVP when switching from 2h to 1hand shield.

Which should I use along my holy 1h:

A holy shield or something more like Icecrown Glacial Wall

Do the block value and doge/defense matter at all in PVP or is it worth more the spell power?

I guess the question is, which shield is best for turtling?

I've been looking for a guide that covers this aspect and I have not been able to find one that does.

Thank you for your help!

Bloodsurge+wrath gladiator's barrier. The spell power and critical will help you generate more art of war procs and privide you with bigger heals and stronger sacred shield.

You probably saw ppl playing preg so thats why the confusion.
When swaping from 2h to 1h/shield best is like said above blodsurge & wrathful shield with crit.

If you go for preg spec its blodsurge/terenas with the icecrown glacial wall.

And if you play prot pvp stil icecrown glacial wall & havoc.

I personally use Wrathful Gladiator's Salvation (caster weapon) and the Wrathful Gladiator's Barrier (crit caster shield) when I use 1h/shield with my Ret spec. There are two reasons why I chose this route. The first being they are caster items, so they benefit my self heals. This is already a bit established by the prior posters, but I put emphasis on this because of how I play when I choose to use a 1h/shield on my Ret spec instead of a 2h. I'm not looking to do damage. If I were, I'd switch to my 2h. What I'm doing is trying to avoid damage, reduce damage I take, and heal any that I do take. This plays into my 2nd reason for my choice. I double down on the resilience items because it reduces the damage I take while I wear them in addition to the caster stats that I get to help me heal myself. Yeah, sure, those stats do benefit my damage a little bit, particularly Exorcism and Consecration. I'm absolutely not worried about haste because I won't be hard-casting - if I get kicked, it's over. I'm absolutely not worried about mp5, because I shouldn't be having mana problems - I have tools to address that (plea, seal of wisdom etc). Crit is the only relevant stat aside from spell power, really, because it helps you to land the crits you need to get Art of War procs, and also helps your chance to crit with your instant Flash of Lights. But even that is diminished against targets with resilience, or if you utilize the crit chance bonus you get from your Sacred Shield procs - which you *should* track, the crit bonus is huge. Which landed me on the item choice I made.

As twinkipro mentioned, though, there's the possibility you're questioning this because you saw someone else using something and that may be because they are playing preg or prot. Both of those things are different from Ret and function in a very different way, which in result causes different ideal weapon choices.