It's been my experience that the nitrite to nitrate is the longest part of the cycle. Cycling can take quite a long time however here is my advise specific to you:
-Monitor your pH and if possible elevate it some. The bacteria responsible for the cycle utilize the compounds that make up the KH and if you get a really strong bacteria colony going and your KH was low to begin with you could see a dramatic decline in pH. Anything lower than 7 pH and their reprodution slows.
- turn up the heat as high as your plants can tolerate while you cycle- this speeds them up quite a bit
-go ahead and add all your substrate. The beneficial bacteria actually only inhabit a very thin layer on top of the substrate. Anything lower than a few microns down and they are not provided with the oxygen needed to sustain themselves.
-lastly this doesn't help you too much now but keep in mind for your next tank (and there always is a next tank, and another, and another...) When fishless cycling it's important to add whatever biological media you will be using, in this particular case it was the foam but ceramic beads are common now too, at the very beginning of the cycle. Though I use activated carbon in all of my tanks, though many do not, I've learned not to do so at the very beginning when I'm still fishless cycling as they will absorb the ammonia needed by the bacteria your trying to establish. Using carbon from the very beginning will only increase the time it takes to cycle.
Hope this helps