Which Indigo to Use for Dyeing?

I'd like to try to grow my own indigo for dyeing. Are all the varieties of indigo equally good for use in dyeing? I'd like to grow it outdoors if possible (in Vancouver, BC--think I stand a chance?), but don't want to sacrifice dyeing power.
What would you recommend?

Only the true indigo (Indigofera tinctoria and the West Indian species, I. suffruticosa) has sufficient indican to give a good blue colour. Wild indigo (Baptisia tinctoria) was once used as a poor substitute for the true indigo, perhaps in times when the true indigo was not available, but I am not aware of anyone using it for that purpose today. Wild indigo is, however, a highly regarded medicinal plant that is still in use. False indigo (Baptisia australis) is also not used for dyeing.
Would indigo produce a crop for you in Vancouver? I think that your season is probably long enough to get flowers. It is at the flowering stage that the foliage develops indican, the chemical that is converted to the blue indigotin in a fermentation process. So as long as you can bring the plants to flower you should have success in making the dye.