Just land softly hehe.
The 127mm fan is not much heavier than the 120mm, just over a kilo complete ready to install. I know most 127mm fans end up around 1300-1400 grams but my housing reduces the weight considerably.
The Jetfan is about the lightest in a quality fan you will get, a little lighter than the 127mm. I would be running fans on the ESC's if you intend to put them into the fuse, you can get fans from hobbywing that are used on their car ESC's and run on 2-3 cells, a small 500mah 2s pack would likely suffice. They are DC motors so directly wired would be fine. Or set the ESC up with the heatsinks facing each other and run a fan in front blowing through the fins, would also work nicely I think.