Charleston is a beautiful city with a lot of job opportunities coming up. There's a huge restaurant scene here and it seems like there's a lot of money being thrown around.
However, its fairly expensive to rent here. I'd try and secure a job before moving here. Some of the factory jobs for one of you alone would probably pay about $35-40K a year. If you don't mind country living, it gets far less expensive the further from downtown Charleston you are. Where the Volvo plant is opening up is in a very affordable rural part of the Charleston area.
The Charleston metro is made of 3 different converging counties (Berkeley, Dorchester, Charleston) with their own tax rates and school systems so there's a bit of a mix here.
I hear good things about Greenville and Columbia, so hopefully one of those folks can chime in. They seem to be in fairly affordable areas with decent job opportunities.
As for South Carolina, we do have an annual property tax on vehicles. Registration is part of that tax, but we don't have emissions. We also have a state income tax of 7%. Property tax is much cheaper than up north and our gas is among the cheapest in the nation. There should be little to no red tape on changing drivers licenses. My impression when I first moved here was that state and county government authorities seemed to take a general interest in saving me money. I was impressed by how well the DMV was ran compared to other places I lived.
As for cost of living try this website to get a general idea.
Cost of Living Calculator | Comparison Tool
I hope that helps.