what fence to choose?

Hi, I am new to this group, and have just purchased a new house on a little over 3 acres in the puget sound area so you are probably going to hear more and more from me. This house is in a neighbourhood and the lots are pretty narrow and long (150'x900')without fences in between.. I have two dogs, one lab which would do anything to go eat the neighbours cat food, and a great pyrenees which is a great dog, but by nature roamers and wouldn't hesitate to take her 3 mile walk in the neighbourhood everyday. I know that my first project will be (i will move in in august) to fence an area for the dogs (maybe 150'x300 or 400') which is about 900 to 1100 feet of fencing... I would like it to be as little an eyesore as possible but keep the dogs in..I have been thinking about invisible fence, but don't think I would trust it 100%, or a regular electric fence with fiberglass posts (which would be cheap...) but would rather install a little more "sturdy" fencing... What do you think would be a good fencing material (4 feet high?) which hopefully would keep the dogs in and not be too expensive...?