Hps all the way. I have a switchable, and both a 1000mh and 1000hps. Such low requirements for lights when in young veg, that both mh and hps had to be distanced. When they could take the intensity, they actually performed a tad better on my hps. Anyhow, even tho ive a switchable, and both bulbs, I run my hps entire grow..(even use the overspill lighting from a 400hps, for clones). Node spacing is less dependant on which light during veg, than intensity i think. Genetics plays a big factor in spacing also. Seems like most stretch occurs during first 20days of flower, and thats hps time either way. Best of luck to ya!