The base is a wagon unit, built completely of wood. I think the key to make sure the basin that holds the water is small and shallow as possible in order to keep the weight down (water is really heavy!). After constructing this of wood we fiberglassed all the surfaces that would get wet. The fountain was designed to operate with about 10 gal of water. It has 2 submersible pumps - the Home Depot variety designed to operate small fountains and waterfalls - built into it. These pumps sit in a small "sump" (not shown on that preliminary plan) that is the lowest point in the basin, insuring that they will always be submersed.
Flexible hoses go from the pumps to the US side of the unit where we built a simple manifold of plumbing parts with a valve for each of the 3 nozzles. We also included a faucet with garden hose connection. When striking the show we turn off the valves that feed the fountain and open that faucet. We run the pumps and use a hose to the sink to drain the unit for shipping.
My first Idea was to use a fan driven by a battery to blow silver and blue streamers in the air. Alas not enough oomph. The second idea was to get a water garden and used the pump to force water in the air. A good Idea I thought but still need to get enough power with out plugging in. So, I walk past the Fish section at Walmart, and what do I see... A Bilge Pump, Runs on 12v power. The pump is designed to aerate minnow buckets for fishing, however if you cut the pipe and install a PVC valve and a showerhead you get an instant self-contained fountain. The Valve allows you to control water flow and my guess is if you get a Fancy showerhead, multiple settings, you can change the spray pattern.
My fountain was 5'x5' with the basin approx. 30"x30" I used a Square flower pot for the basin and lauan covered with plastic to catch the water and direct it into the flower pot.
The pump cost about $20.00, and I used a motorcycle battery to run it. The battery was $30ish (Didn't use my Harley Battery) and I used a Cheap Shower head, so that might be costly. Oh and last you will need a battery charger, also about $20.
The sound of the water splashing on a hard surface can be controlled by using "hogs hair" (
http://www.airconditionerfilters.net/?page=customer_service.html) which is used in movie making to help with the noise of rain effects on a sound stage, or on location put on roofs of houses to control the sound of rain, real or FX, hitting them. The FX guy will put a pad of this stuff in the bottom of a bathtub to help with the sound of the shower as well.
Leakage... check out pond liners from a local garden store or landscaping company. Used one in a project not too long ago with a gazing pond 12' x 6'. I was quite impressed with the material. It's about 1/8" thick and very tough. It also doesn't leak.
The two things that I do to prevent leaking is that when I construct the fountain I use silicon caulk (not the half and half) instead of glue on all the joints. I then fasten them with screws as usual. I then paint them with pool paint. This has been very successful on all of the fountains and water pools that I have made.
We made the fountain on a wagon as a half-circular affair. We had a large half circular piece of lauan as the back. On this we made a faux tile border. We used an off-the-shelf lion's head as the main part. The actual "fountain" was a $40 aquarium pump. It obviously needed power run to it when it was moved. The large basin at the bottom was just covered in thick plastic (carefully.) The smaller basin under the lion's head was framed in lumber and screening, and we used some joint compound to finalize the shape. We covered this small basin with Sculpt -or-Coat.
The different patterns of water required for this project will need more thought, certainly. I didn't have that headache to deal with. We also didn't need a self-contained power source. It sounds like yours will move more. I would use battery power if I needed to move it a bunch.
People have mentioned weight. I think water is about eight pounds per gallon, yes? On thing we didn't think of at first (doh!) is that we could move it quickly, but it sloshed quite a bit when stopping. It is obvious, yes, but...
Take a careful look at your sightlines. We were looking at having to build several rather large fountains for Die Fledermaus last year. We examined sightlines carefully and realized that no one could actually see into the fountains. So we were able to use a 5 gallon bucket with a
submersible pump. We had to aim the Cherubs just right so they peed in the bucket, but it was so much easier than we had been expecting.