A pond waterfall kit may, or may not, be the answer to your particular situation.
Components within a waterfall kit are designed to be constructed seamlessly. A decent water garden kit will include all the types of filtration necessary to keep
water quality
optimum.
Filtration systems including skimmer,with
biological filtration,
‘filter fall’, and possibly
UV light
are readily available. They offer good direction and ease of purchase for the different components. You'll also know that the different parts are sized in proportion to each other. Which can be tricky to the novice.
On the other hand, not every component in a backyard pond kit is necessary for every water feature. Often a kit will include items like fancy filter media, lights, under layments, etc., that may not be absolutely necessary to get a your particular feature built.
**The most basic plumbing design includes: (1)Skimmer w/pump chamber,(2)Pump, (3)Flex line to (4)Filter-falls pour over filter. Add a liner with a twenty year warranty and you're well on your way.