If you're going to take a stab at the gunboat, I believe the discussion resolved at a consensus between Chief and Brand to go towards a slightly larger two-seater (side-by-side) with strong lambda shuttle cues. The Missile Boat is a completely different ship and there really hasn't been any talk about it that I'm aware of, so take it in whatever direction you wish.
Personally, it was never my favorite ship at all (and yes, I played all the way through Tie Fighter and XWA) so I'm looking forward to seeing if you can come up with something that will wow me.
Edit:
Ok, we probably should have some discussion about the direction this ship could go in, especially if both the gunboat and the missile boat are going to make it in. I think it's important that there are distinct differences in their roles. In my mind, the gunboat is a larger, less maneuverable but extremely hard hitting and packing heavy firepower suited to taking on larger capital ships or installations. Instead of a space supremacy fighter (which the Empire already has in the TIE Fighter and Intercepter), perhaps the missile boat should be loaded with smaller but long range anti-starfighter missiles that can be used in an area denial role. Deadly at longer range, but can't go toe to toe with an X-Wing or A-Wing if it's able to bring the fight into close range.
Those are just my thoughts, and hopefully a way that could make this a useful and unique craft without it being hated for being OP.