Check to see if there is a pond society in your area. Pondering is an addiction, and an expensive one at that. If you are not handy with concrete, shovels and masonry, it may be worth your while to pay someone to do it for you.
Here are some pictures of one I did a few years ago:
That is the top (small) pond, the stream exits to the right and flows down this:
To a lower pond, shown in the back ground here:
The water is circulated from the lower pond up to this small waterfall:
The entire installation was only 50'x50' and gave great water noise as well as requiring no filtration and accomodating a large amount of fish.
All constructed of ferro-cement and leak free for at least 10 years to the present.
This is what it looks like grown out from the low side:
This is what I started with: