Hey guys, I recently heard LoTR is going to stop so I thought I would get some minis now.

My main wish is to start a dwarf army so my question is, which elites are better, Khazad Guard or Iron Guard?

From GW site I would say Iron guard is more popular because they are made in finecast, but many people take Khazad Guard, why?

Def 7 is the main reason. Still wounding on 6's against str 4 is really helpful. There also one of the only good warrior to have str 4 so there optimised to face against evil's most common and effective combo which is str 4 def 6.

Both!
Khazads are as tough as a Dwarf with shield, but break through enemy armour easily with S4 and, if needed, two-handed weapons.
Iron Guard are the reason why Dwarves don't really need spears: they have two attacks all by themselves. At S4 too. Main downside is D6 (strange to have that as downside, but in comparison to other Dwarves..), so vulnerable to S4 themselves. They're absolutely great, but too expensive to really take a full force of.
Some Iron Guard, a good amount of Khazad Guard and other than that plenty of normal Warriors (not bad at all either) should form a solid basis for any Dwarven force.

I am currently trying out no more than a warband of each one and suffice to say they are proving very very deadly. I am playing Easterling next week so i wonder how they will get on then.

The best "Elites" are indeed the Vault Warden teams , D9 at the front = 6/4 to wound at S4 ... costly but Elites are USUALLY costly that is why they are "elite" i.e top 10%

Hold on, who says it's ending?

It's just that metals are slowly going oop as well as really unpopular finecast, mounted wraiths, corsair command ect.