Brad- it basically is 6 top boxes, 8 wardrobes, posts, coving and skirting. All assembled and connected on site. Everything is done on measurements, its the only way to do it, theres never enough room in a workshop to set something like this up and if there is you have too big a workshop.
The secret is knowing how it all joins together without big joins showing, all the joining screws are hidden behind hinges. Practice makes you very confident that these large pieces will fit ok, but mistakes do happen from time to time, I always think overcoming mistakes is one of the most important factors in this business.
With regards to payment stages, this actually only took 4 weeks as there are two of us in the business, 160hrs each, we normally take a third deposit, a third on delivery and a third on completion. However this customer did half (deposit) and half.
If you start to take on bigger jobs my advice would be to spend hours on your cutting list, and really think about how each unit or part is going to join on to the next. Make sure you incorperate scribes into the job so that you have some room to play with.
If I can advise you in any way feel free to pm me.