As in all of aviation it's a function of ratings and hours. I would say that 2,000 hours is the bottom number for getting seriously looked at for an entry level position. And a part of that needs to be multi-engine. Again very subjective. Salary is something else that varies widely.
Pay is based on geographic location, size of company, type of airplane etc.
Captain vs. Copilot. But I could safely say that salary could run from 20,000 to 120,000 per year, depending on the factors I've mentioned. The good and bad parts of corporate aviation differ from individual to individual. Some people would say the travel finally gets to them as well as the issues of no set schedule. Others wouldn't dream of a life without it.