You can use the 13w 2700K along side the 5000K 13w one, babies don't need too much light for say 1st week and half maybe, Try and Raise the Bulbs to say 3" from the Tops, Also if You can try and Turn Bulbs Horizontally, Vertical is good when plants are around the light source and Horizontal is better for plants when directly above...IMO...more light spread...
Depending on which way You going to Go??? But after say week 2 You really want at least IDK? 125w 6400K above her, then maybe 250w Giant CFL or move up to 250-400w Mh/Hps Setup...Like I says depends How You going to Do it, and of course Your Budget.
atb