A rapid route to a modern coastal combat boat

What size and design should a modern motor gun or torpedo boat use if ordered within two years?

Start with an RNLI lifeboat hull and modify it for combat; missiles are suggested, but no exact dimensions are given.

For a modern gun or torpedo boat needed within two years, an RNLI lifeboat hull is proposed as a starting point. Adapting an existing hull offers a route to getting the craft into service quickly. Missiles are suggested as a likely weapon fit in place of torpedoes, although no precise size or completed design is specified.