I have no idea as to which model I want.
4.7 inches or 5.5 inches?

!!!!!

Same here!

I hate "thinking" something is on my device only to find out I didn't sync/download it. This time around I'm being prepared.

Damn you to hell Apple my purse is not ready

I suppose it depends on what you're looking for.
The 4.7" phone is expected to be cheaper than the iPhone 5s (not by much though, but it means you can use that money to decide whether you want to splurge on a bigger phone).

will the note 4 be as big as the ipad air?

The Note 4 will be around 5.7" though they may bump it up to 5.9" or something though.

The phone will be bigger obviously, but don't take rumors as facts (not talking about OP, but the specs listed here, some of it could be very wrong).

I also want to have a readable screen size with a lot of information for in a car mount. Checking slow traffic for driving around it, lurking/posting on fora, watching videos,...

They are confirmed from the production line. Sapphire Screen, A8 chip etc. have all been leaked.
Same with the screen sizes and thinness etc.

We're only commenting things that are confirmed direct from the source. Only thing that isn't confirmed that we have posted is the final design.