OK 6500k is the "Daylight" bulb, it has a blueish light to it. These are good for veg, they come in 23w and 42w in almost any big store. you can find others on the interweb fersure.
Anyhoo.....2700k are the red spectrum "Warm light" bulb. These are good (as an assist to HPS or HID) for flower...