In order: no, you don't need a new bulb for the plants -- anything in the 4000° - 10000°K range is considered 'daylight'. The real difference in the temps is the color of the light -- it's reddish towards the lower temps, and bluer towards the higher temps. So 9000°K is fine.
Florescent tube hoods aren't like incandescent bulbs -- the wattage of the tube is determined by and fixed by its size. The only way to go higher wattage is to get a longer tube.
For what plants to use, read this:
General Guide to Low-Light Planted Tanks
As for sources, I've had a great experience with LiveAquaria.com. Others here have had good experience with azgardens.com and aquariumplants.com.