Great job! Looks awesome. And yes, it has fat engines. The only reason I haven't gotten a few -300s to make some customs myself. They should've used the same engines as on the 100. From what I'm aware of the engine nacelles are the same. Only changing intenally.
The best -300 in 1:200, for me atleast, is the a-net model built foe ANA. The only drawback is the way the main gear is fitted to the nacelle. But that can be fixed with a little modification.
I'm thinking of getting a -300 3d printed to make a few customs.