from my experience and from what i've read, plants need 3500 lumens per sq ft.. they'll grow as wide as a sq foot in radius and even wider... provided that, your 2700K bulbs are for flowering, u need the 6500K for optimal effects, but i started out like you and had to use what i had at the time.. at avg 9600 lumens @ 2700K ur good if u concentrated those lights solely on two plants.. extra plants means extra lights from that point out.. if you're looking for optimal, that is... warm spectrum (2700k) light is ideal for flowering, while cool spectrum (5500-6500k) is ideal for vegetation

running back and forth to walmart, my setup cost 290 and thensome for 'upgrades' and tweaks.. those lights will keep your plants alive, but you could get more out of them if you gave'm more light (more photosynthesis) and an appropriate spectrum (faster rate of photosynthesis)

the plants will double in size usually when flowering so keep that in mind when it comes to space.. as for heat, ideal temperatures are between 73-85 degrees i'd say.. if you can avg out at 80degrees, you should be fine