I know we don't have all the information regarding engineers, but, if you could use your imagination, what ship would you like to modify and how would you modify it. The only limitation is that your hull size must stay the same size and you cannot add significant weight to the ship.
For me, I would modify the FDL, the reason I would pick the FDL is because the looks of the ship
I use to be a clipper / cutter guy, but since I reset my game, I'm more a FDL guy... I know this is not the popular opinion, but I like the luxury killer look, and I'm ok with being an odd ball! The glass moon roof, is also VERY nice looking. Is it the bedroom? If so, it reminds me of guardian of the galaxy when he forgets there is a girl on the ship 
1) I would drop 2 utility mount A Shield boosters and save 7T's of weight.
2) I would use the 2T' of the 7T's to add one size 1 internal compartment so that I could add a DSS to the ship.
3) I would use the other 5T's to up size the fSD to size 5.
My intent is to increase the utility of the ship.
For me, I would modify the FDL, the reason I would pick the FDL is because the looks of the ship
1) I would drop 2 utility mount A Shield boosters and save 7T's of weight.
2) I would use the 2T' of the 7T's to add one size 1 internal compartment so that I could add a DSS to the ship.
3) I would use the other 5T's to up size the fSD to size 5.
My intent is to increase the utility of the ship.