Wow you could put together an amazing planted setup in a pond like that. Do you have plans for lighting yet? Will it get natural light, or are you going to use fixtures? I imagine that you might do best potting your plants in regular flower pots or pond baskets, although you might find it handy to hang some planters form the sides too.
Fluorite will work real well for potting up the plants. Any of various similar products, such as Schultz Aqua Soil, will do fine too.
I have lots of experience with growing these plants in indoor pond/riparium conditions and I also have some good sources, so I could help with that as you start planning out the plant selection.
There is a lot of crossover for plant care methods between ripariums and indoor ponds. You can find quite a bit of information on ripariums over at
The Planted Tank Forums. Just do a search for "riapriums" over there and you will get many results. There is also a new
Ripariums sub-forum over at
AquaticPlantEnthusiasts.com that just started up but is already pretty lively.