http://www.headsite.com/purple-power-seeds---female-seeds-232-p.asp is this good is it auto flowering?
Purple power is mostly sativa dominant, and is medium to tall in height. It is not an auto flower, and should be grown outdoors.
I would base things off of sunlight for the UK, don't go for a plant that needs a lot of rays, you are in the clear with a purple/blue strain, they love lower ambient light, and produce more color when in darker areas. That would be a good strain, it's relatively easy to grow. Keep in mind the type of weed it is, that is sativa (head high), if you don't like a head high and prefer more of a body high, then go for a indica dominant plant: http://www.headsite.com/blueberry-seeds--dutch-passion-feminised-cannabis-seeds-1-p.asp or http://www.headsite.com/blue-moonshine-seeds--dutch-passion-feminised-347-p.asp