Hi every one. I am new to vegetables under lights, not new to gardening.

so here is the set up, kitchen counter,good soil,buttercrunch lettuce growing fast and crunchy. Two 4'shop lights with 32w 4100k tubes on 13hr. timer. Garden space about 1x4' I am harvesting two heads of lettuce a week and have some room and desire for some variety, I like lettuce fine but....Please Someone some ideas? Pock Choy? Swiss Chard? Do I have light for more than lettuce?

Thanks I feel like a rabbit, Curt :-0