thanks all!
1st: the B2 spirit and her predecessors as well as/and especially the German WW2 designs by Horten. Nothing says flight like a big wing.
Also I needed to intergrate the Bird elements as well.
2nd: the two inner nacelles can be swapped out for extra plasma cannons (DNH model). in later models the nacelles are doubled up at the wings , and the plasmas become standard...
3rd: 4 nacelles not 6, and one main impulse assembly in the "tail" with 2 more on the wings for manuvering (just cause she's big doen't mean she's slow or unwieldy)
4th: 320-350 metres long by 640-700 metres wide (I haven't settled on it yet).