what plants did you want?
what size is the tank (how high, deep and long);
There are lots and lots of cheap alternatives, to what is otherwise an expensive aspect of the hobby.
as a general rule most people on here, with great success will use 6500K and 10000K spectrum lights.
18000K lights are also available, but are horrendously expensive (as t5 HO tubes - ~$60+ each) as compared to the others that you can get from an electric supplier for $5-10.
I use 18000K tubes, and the plant growth was phenomenal. the other spectra seems great too, as heaps oof people on here use them with great results (have a look in the plants section).
but another aspect is that the lights have to be powerful enough to penetrate the water, and reach the base of the tank, so plants can fully utilise the light that does reach them.
HTH