I'm in the exact same situation your in. Were an S-Corp, with two owners, running two 2500HDs. Due to financing, heres what both my accountant and insurance agent advised. Each truck has a magnet on it, payments are covered as marketing/advertising expenses (similar to how redbull vehicles are covered). Insurance wise, each vehicle is covered under a fleet policy (held by the company) that handles $1 million plus per vehicle. Anyone who drives the vehicle is covered up for a $1 million +. Anyone who regularly drives the vehicle must be added to the policy to insure protection.
Generally this should cover almost any problem that happens. Just be careful who you let drive your vehicle. If you do decide to put the vehicle in the company's name however, I'm not quite sure accounting wise how it works, but I'm pretty sure you would actually owe the company for any personal use of the vehicle. But I would definitely double check on that with your accountant. I know tax wise you would lose any write offs for mileage.
If you decide not to put any company logos on your truck and keep it in your name, you can reimburse yourself for mileage. But definitely talk with your insurance agent and accountant to decide what option is best for you.