Regarding the Geb and Resheph, from my point of view they should have similar shape to the Osiris, as that one was the basic for both designs inRP, though you can heavily modify the frame. Don't know what Omicron as leader of Order| will say about it. Or just look at his first post in here.
*Edit*
Just got an idea for the Hathor: How about you take some inspiration from this Assault Dropship from Battletech?