Of you're painting a Gibson Les Paul, do NOT use modern automotive paints! Most modern automotive paints are some sort of polyurethane. This is the type of paint that is normally used on Asian-made guitars including Epiphones. The benefit to using poly is that it is extremely tough-wearing, meaning after the paint has cured, it's almost like a layer of plastic covering anything you painted. It's a durable, long lasting solution, but its not what most high-end guitars are painted with.
The paint that Gibson has always used is called Nitrocellulous paint. These types of paint were used on cars back in the 1950s, but they were restricted due to their environmental impact. The Nitro-based paints are her best option for refinishing a music instrument, such as a guitar, because the paint after its applied is usually pretty thin in comparison to other options. And, Since Nitro is thin and pourous, it allows the wood underneath the paint to breathe, and allows the wood to age at a more natural rate. Some say this has a beneficial impact on the tone of he guitar, while others scoff at the idea that paint could have any impact on the tone of a guitar. Another benefit of Nitro is that if you ever get a chip or a scratch in the guitar's finish, it's much easier to fix it using Nitro, and most times, you can't even tell when a repair has been made.
If I had any guitar stripped down to wood, I would choose to refinish with Nitro over anything else. I don't really care for how poly makes a guitar neck feel, plus, I tend to prefer the way Nitro finishes look opposed to poly.
As for where to look for Nitrocellulous paint, check out companies like Reranch or even Stewmac sells Nitro paints. They're pretty easy to apply...just remember...thin coats...