Giant Yukon vs. Iguana

Hi, I'm new here. I'm about to begin a tour in Taiwan and I need advice on 2 bikes. Yukon and Iguana. I plan to purchase this bike in Taiwan as it is MUCH cheaper there than anywhere else. I converted the price to USD as follows.

Iguana-$360 (SHIMANO DEORE, disc)
Yukon-$240 (SHIMANO ACERA)
Yukon w/ disc-$288 (SHIMANO ACERA, TEKTRO disc)

Is there a really big difference between the components? Are disc brakes really that good? Is it really worth it going for the Iguana?

anybody?