Chirta of some sort

[TheLorax]

I suck at house plants. I have some sort of a Chirta cultivar that is in a glazed ceramic pot in my kitchen window. I don't recall what mix I re-potted it into a year ago. The plant has doubled in size but the stem is rising above the soil by about an inch or so. I suppose it wants more light. I'm going to have to re-pot this and would like to know what medium to re-pot it into as well as whether or not I should re-plant it at the same depth leaving it rising above the level of the medium or if I should set it a little deeper? I was thinking it might be best to set it a little deeper to eliminate that legginess but don't know if it would be appropriate or not to do this.

My plant sort of looks like this save a few differences; mine has never bloomed, my plant's leaves aren't that deep of green, and mine is leggy-
https://www.flickr.com/photos/kschmid/112267440/

What type of fertilizer or soil amendment for Chirta spp?