I wouldnt try all 3 at the same time right away as mentioned. Especially if youre not familar with any of them.
If youre having trouble eye balling food quantities and calorie profiles, I would suggest Zone first. The one thing I got from reading the zone book and trying it for a few weeks (it wasnt for me) I became really aware of how much a serving of one thing is versus another, and what kind of nutrition profile it had. And just use things youll want to eat for IF.
After youve gotten the hang of the lower calories and better food choices, id say experiement with IF and see how you like it.
Zone ratio for IF is crazy though, unless youre eating dates or something super carb dense because it just gets to be a lot of food in that short time.
Zone worked well for me, and many others over at CF. It was just too much work trying to eat 5 times a day with work/school.