2 Coladas, 5 Tizzie turrets, SNAC and Screamer and you'll be able to take down pretty much any Gunboat you meet with relative ease, including Nomad turret Scorpions, it's -that- powerful.
Though if you're looking for a VHF to take on Gunboats, either get an Inferno Sabre, or become extremely good with mines and rely on Screamers, as the only real problem when fighting a Gunboat in a Fighter is it's shield.