To build exactly this deck you need many expansions. I was lucky enough to get a collection including multiple core sets on Ebay - then my wife offered me the few most recent expansions.
But there are many very efficient decks that can be built with a more limited pool of cards.
Let me attempt to rank expansions in terms of efficiency:
- Foundations of Stone is probably the best one.
Glorfindel (spirit) is an amazing card, and he is coming with his toys in the same pack (Light of Valinor and Asfaloth). The pack also has 'Daeron's runes'
Glorfindel opens a lot of possibilities for your decks.
- I'd put Watcher in the water in second
Aragorn is an amazing hero, and there are a lot of very good cards in the pack: Arwen Undomiel, Legacy of Durin, Sword that was broken and Elrond's councel.
I also think you can build a very efficient dwarf deck with a few expansions like The hobbit: Over hill and under hill, Return to Mirkwood for Dain ironfoot, and Khazad-Dum