Thanks everyone
I already feel better educated about knives

At last , I found a knife that looks like what I have mentioned in the first post.
It is the Wharncliffe blade



From what I have read, it is mainly used to cut line and seems to be the last choice in my case.

The Tanto design, however, has a potential for a survival knife. While I am not looking forward at stabbing a grizzly with it, I think it can be a good tool for diggging in the ground if your are in an emergency. The tip is less likely to break with this design. Plus, if the straight edge is meant to cut throats, then it is great for cutting game meat. It may not be so great for skinning though.

I agree about the serration. Most serrated bladdes I use around work and home (opening boxes, cutting cardboard and such), and for most of these jobs a full serrated blade is needed (not an inch or two). Even outdoors, if you have to use a serrated blade as a saw, two inches of serration won't help you much.

Now, another question about short-wide blades. What are they used for? I have seen one and like it very much but have to learn its ups and downs before making decisions.

It looks like this