RE: Which Yak ?
I`ve only had the .40 Yak from Hyperion, none of the ones you mentioned. VS is 54,3", and I use the motorkit they deliver: Hyperion 4020/14 and the 80A ESC.
Have flown for some decades, and I think the Yak is OK. I power it from 4S LiPo and 14x10 APC-E propell. After some tweaking it flies good acro, good verticals but often get a noseover when landing on grass. Since I have got really tired of 3D I prefer acro-ability. But those of my friends who still like 3D use a 5S LiPo and 15x7 - 16x7 propellers. Then the power is enough for hovering. Landinggear were a joke, have put on a glassfibre gear.
Would have tried the EF today instead I think.
My 2C.