Just started building a new model for a 90mm fan unit.

I ve decided to go electric, and have settled on the WemoTec Midi Fan , (Ø90mm)

I have been recommended the following setup,

Mega Motor , 22/30/2
5 s Lipo 3400
Jeti Spin 66 ,

Hopefully all in she'll weigh in at about 2 -2.5 kilos , but all the above numbers are new to me, and I just wanted to "get a second opnion" .
Also how do you estimate power consumption ? , obviously V×A =W , but how do you estimate the current draw of the motor and fan ???

cheers Nick