if you care about the symbolism at all... there could be a lot to this....
i would say put a lotus in the center... it is one of the eight symbols of buddhism...
i think it sort of symbolizes growth and enlightenment... the flower roots in the mud, grows through the water, and the flower blooms in the sun far above the surface... higher above than other flowers because of the strength of the stem..
the two fish, or golden fishes (goldfish), are also one of the eight symbols.. though both fish are usually upright, and not one upright and one upside down... they symbolize two rivers in india that represent the lunar and solar channels...
they also symbolize happiness, fertility, and unity...
i have wanted a goldfish tattoo forever.. but decided to go with a lucky cat, lol.
but you may also not be about buddhism as i am.. but its just symbolism...
just a suggestion..! its very cool, whatever you decide.