One model which worked well in Epic was Pulsa Rokkits.
There use to be a metal version for Warhammer 40K, but Pulsa Rokkits were kind of ignored for a few years
In the current version of Warhammer 40K there are no models and no rules in the new Ork Codex. However there are rules for Apocalypse.
As a result I am thinking about building one for my 40K Orks using a 1/300th Space Shuttle kit.
I am less interested in the Shuttle, more interested in using the rocket boosters and the fuel tank!