To me, the concept of Heaven seems to be a catch-all word for a physical "place" which makes no real sense since we have no physical need for it. Most people seem to think of it as a realm where the soul spends time when not in a physical body, or maybe where the soul remains while an aspect of that soul (a personality) dwells in a body.
Your first question, Does heaven exist in reincarnation? - I think the concept of a place on the other side of the veil would fit in the general concept of Heaven, although I doubt that it is a "place".
Your second question, ...is there a good reward waiting us? - I've never understood this, I always considered the whole process as an evolution of a soul's progress, neither reward or punishment. Another thread where the question of "fairness in life" being expected was equally foreign to my way of thinking.
It seems to be that we are each given memories and experiences that hint of dimensions that we can not control enough to bring into scientific methodology to study and build upon, we just get pieces to let us know that there is more than we are currently experiencing - some are given more pieces than others for some reason.