Hmm...
I think I like the Terran-Vasudan hybrid idea. I know this model is different from the typical bulkier Freespace universe ships, but perhaps Terrans and Vasudans are moving toward sleeker ships for whatever reason?
I think the thin neck might lead people to get the impression that the ships is fragile, and thus it might not impress on people immediately as a destroyer. However, the Hatshepsut also has a long thin neck although its a very wide ship.
I was also thinking that the windows would be a bit big, but I haven't gotten around to playing with that yet.