As the CFI checkride Oral is about 8-10 hours on the first day, and about 4 hours on the second day, to include the flight of about 2 plus hours, I am not sure how you are going to do your CFI on the cheap.
As an instructor whom teaches CFI students, I can tell you that is just not going to work. There is just too much to chance. And with about an 80 percent failure on the first time through, you just can't cut the training.
You have to be very good at handling all the knowledge, lesson plans, teaching techniques, scenarios (etc..) and you better be on your A game. This is going to be one of the, if not the most difficult checkride you will ever take.
So I can tell you this, Go somewhere to great training and learn what you need to know to be a good teacher of flight. That takes time and money and if you are not able to do that, then please don't. I am not flaming on you, it is just that I do this every day and I know what works and what does not.
And no, you cannot do both your CFI and your II in both days. Two full days for the CFI. And a very long day for the II. And for the II, you better know what you are doing on instruments, let alone being able to multi task the teaching, being ATC, working ATC, and flying all at the same time.
And all initial CFI checkrides are administered by the FAA. Can't use DPE's for the initial. Again good luck to you. But talk to those of us that know and do this every day.
Justin