Your saved games from the original D2:ED will not work with D2:DKS

If you're on the xbox you will have to start from scratch as from what I understand, you cannot buy FoV separately like you can for the PC.

Also, don't know what you mean by DLCs...

If you just buy FoV then you can import your character directly into it. Otherwise if you buy DKS you might have to play through again.