I haven't built the WM or Yellow, yet. I do have the Kangke and if you haven't already you can check it out
here.
I think the H9 is the cheapest... I want to build one of those, too. And, see how it compares to the Kangke... the Kangke flies really well.
As for motor... I thought the OS 1.60 was just adequate for the 11-lbs Kangke. I, personally, wouldn't consider YS-120 on one of these CAPs... unless it was just for cruiz'n.