Hi peggymacleod,
Post #2 here includes the factory direct manufacturers in and around Greenville, SC.
Innersprings are just a support system and there are many different types and they can all use a range of different comfort layers on top of them as well. There is a step by step guideline in post #1 here that will help you find the best mattress for you and includes some links to sections of the site that will give you a good idea of the many options that are available. It helps to think of a mattress as a support system for spinal alignment with comfort layers for pressure relief on top and both of these can use many different materials.
Like you … I am not a fan of airbeds as you can see from this article. Air is not a great support system IMO even though they use the same comfort layers as an innerspring mattress.
You have some good options within reasonable driving distance which should give you some good quality/value choices.
Phoenix