Yey!!! for bike shopping.

That could be an ok bike (depending on your expectations), but I would at least pick one of the bikes that had v-brakes instead of the disc brakes from that site. Its rare to find someone thats happy with their cheap disc brakes. 7-speed freewheels are pretty common for the entry level bike in some maker's line including the Trek 820 and its ok for the price.

What type of off road riding are you doing? If its nothing too serious the hybrids without the suspension forks on that site are a better value in my opinion even though I personally generally like 26 inch wheeled bikes, but not everyone does obviously.
You will get lots of good advice here. Good luck with your search. I would help more, but I don't know your market over there.