Got an edited final version after adding some more data. Still not super happy with the overall colour. (keeps getting a really strong green after stacking, even though the individual subs don't show it.) I assume it has something to do with the light pollution from my backyard as I don't have a light pollution filter yet...
This is around 50mins worth of 2min, 60sec, and 30 sec subs at 800 iso 250mm FL, F7.1. (tried to stop it down to keep the abberations of the lens to a minimum). Darks added and stacked in DSS with a bit of touching in Photoshop. Cropped to remove some vignetting/ distortion at the edge of the frame.
But for my first image on the HEQ5 pro and 55-250mm lens on an unmodded dslr overall I'm happy with the outcome. Can only get better from here