I cannot give you a definitive, mathematically correct answer (because I am unsure if the relevant theorycrafting has been done), but I can at least give you my thoughts and anecdotal experiences.

I believe that the answer to your question depends on a couple key factors:

1) Whether you raid 10-man or 25-man, and
2) The composition and skill of your raid, as Padruthor noted above.

I see more value in focusing on stamina in 25-man raids. The point at which you will probably see tanks try stacking stamina is when they get to Heroic Warmaster Blackhorn, where getting one-shot even with a large chunk of health remaining is a real possibility.

I tank for a 10-man raid with a Holy Paladin and Disc Priest as my healers, plus a Resto Shaman for 3-healer fights. I currently match all socket bonuses: mastery/parry in red slots, mastery in yellow slots, and mastery/stamina in blue slots, and I reforge with a focus on mastery. I also use a Lichborne spec rather than a higher-DPS spec because my raid's DPS is quite good.

I can say that this setup has been adequate for every fight up through 6/8 Heroics cleared. In addition, during our Spine attempts so far, my survival has not been the issue. Whether or not it is optimal, I cannot tell you for certain.

quick question, i have looked the pve BiS guide for DW frost DK's
i currently have access to

normal DS 10 man (4/8)
raid finder + heroics

some items are really easy to get :
( valor back + relic + neck )

but as far as the other ones goes
are the "same vertion" of items but lower ilvl are the best in slot in that ( braquet ? of ilvl ) ?

i hope my question is clear.
i will try to reformulate
[Treads of Crushed Flesh] 410 ilvl = curently the best in slots
[Treads of Crushed Flesh] 384 ilvl = the best in slots if i only have access to 384 ????

one other question, why is expertise rated so hight in stats priority, every where i look its the botom one
and here its just under hit

Expertise is ranked highly for frost DKs to the soft cap because as a frost DK a large portion of your DMg stems form your obliterates and your frost strikes. What further increases the importance for this stat for frost is that your RP dump, frost strike, counts as a melee hit and if it is avoided, you gain no dmg from the rp expenditure as well as losing the potential runic empowerment proc. This is different than unholy because an UH dk uses Death Coil for the rp dump which is a spell not affected by any avoidance other than hit rating. So it is possible that the guides you were looking at that ranked expertise poorly were actually guides for UH dks and not frost dks.

Looking at those 2 weapons, it really does not make much of a difference because both of them have the same weapon dmg and swing speeds, which is what in most cases is what makes the determinant between which to put MH and which should go OH, as all the other stats affect both MH and OH equally. Generally as a frost dk you are going to want the weapon with the higher weapon dps to be in your MH as your MH weapon is never going to miss on a white swing (assuming 26 expertise and being positioned behind, as you should be), whereas your OH is going to be missing a good chunk of attacks as you only stack your hit rating to spell hit which leaves the OH white swing hit chance rather low. In the case of weapons with procs (Souldrinker) things can get a little more confusing because then the proc has to also be taken into effect, but as a general rule just look for the weapon with the higher weapon dps, and this is supported even in the case of Souldrinker basked on the reading for frost that I have done.

Edit: Your racials could affect the choice slightly as well depending on if you are a race that gets expertise bonus to a particular weapon.