metal hallide is the best for them if you look on ebay there is a guy selling refurbished metal hailde with everything new beside the ballast is used. but you will find since its used the price is half compared to new. just depends if you want a new one for that size of tank your looking in the hunderds for that.
also depends on how deep the tank is? i assume you might be able to get away with one mh
the anemone would just stay on one side of the tank. but i am pretty sure you would need at least two metal halide to cover the tank from end to end. and it would look better to.
heres the light i was talking about