Looks like some really good possibilities.
I like the pond and stream concept.
Here are a few things to consider.
1) Have a licensed electrician do the wiring and get conduit and a GFI circuit out there for the pond.
2) Sun is not a problem. Good light is important for pond plants. How many lakes do you see in the forest, under the shade of the trees? And if there are, the plant growth is not as lush as it is in the sun.
3) Use large enough plumbing so the water flows well, looks good. A mag drive pump is more efficient, but works better with somewhat larger pipe sizes. Flexible PVC is a good way to go. Minimize fittings.
4) Do not pile up soil against the house. Do not pile up soil near the house that would direct rain or irrigation water toward the house.
My set up is similar to yours. Here is how mine works:
Upper pond is a 45 gallon pre-formed pond, roughly rectangular.
Above this are several boulders. We used colored concrete that matches the boulders to hide the pipe. The water comes arching out of the pipe and falls in the pond. There is enough water hitting the boulders that moss grows on them. Make sure you have pond liner under and behind the boulders.
An alternate to this is a type of product that combines a water inlet and a water fall, and this container also holds some sponge filter material, and some bio media. One company that makes this is
Back to my set up...
The water falls out of the 45 gallon pond because I installed it with a bit of a bow in the front. It spills over onto a rock. There is a void behind the waterfall in front the face of the pond. This is an echo chamber. It enhances the sound of the water fall. Tuck the pond liner well up around the upper pond. You can lose a lot of water to splashing.
Near this is a bridge. It is not much. Just make sure it is well supported. Near the edge of where you dig out for a stream there is not a lot of soil to support a bridge. You might need to pour a concrete pier at each end of the bridge.
I dug a hole about 10' wide and almost 20' long.
I lined the whole thing with pond liner.
Then I filled it about 3/4 with peat moss, leaving a winding path through it for a stream. I used a special kind of weed mat to keep the peat moss confined, and lined the stream sides with cobbles and smaller river rock (cobbles up to 10" diameter, river rock down to 3/4").
The peat moss stays damp, and I have Canna, Calla, Japanese Iris, Sedge and other marginal plants.
At the end of the stream there is a rock that is VERY carefully installed so the water shoots out over the rock and falls into the main pond. There is expanding foam filler that is black, and designed for ponds to help direct the water OVER the rocks. Without the EFF the water would simple flow around and under the rock and there would be no waterfall. The construction type works just fine, too, but is glaring yellow, and shows up all too well. The black pond product is much better.
Again, an echo chamber under the rock, because this rock hangs out over the pond. It is supported by other rocks and a concrete block. Still plenty of space for the sound to echo.
The main pond is about 200+ gallons. It has a shelf around most of it (Well, about 2/3) and a deeper area. The soil does not freeze here. If it freezes in your area make sure you dig deep enough. Consult an expert.
The pump is in the main pond, in a box with some poret or matala mat style of coarse media. Easy to rinse out, but allows very good water movement. The plumbing escapes over the side of the pond. I did not want to attempt a bulkhead fitting in pond liner. The pipe is hidden under some rocks.
I was using a sump pump (to pump out flooded basements) but it burned out when some roots tangled in it. I will go back to a real pond pump and better protection.
I think I will dig the main pond a bit larger in one area and make a plant-less area for the pump. Easy access for cleaning. Aquascapes makes a box for this, too. See their web site for more ideas.