Welcome to the Forestry Forum Steve! I hope you stay and enjoy the friendship and wealth of information here.
I'm not a sawyer, logger or forester, but if I was running a business selling flooring and molding, I would use kiln dried just because the end product would be more consistant and have less movement. I certainly don't want to get into a discussion on Kiln Dried Vs Air Dried, 'cause it's like talking politics or religion.
To get number of board feet in a log, look to the left of the screen and click on TOOLBOX. You should find some calculators that will help.
I don't have anything against old, good quality tools, if they work well and are pretty much maintenance free. If I were running a company making moldings, I certainly wouldn't want any downtime from breakdowns or just having to stop and oil bushing bearings. Buying something cheap might end up to be more expensive than buying new. I'd want something reliable with new technology and sealed roller or ball bearings. I'd buy from someone in your area so if you need service, you can drive over to get the part or talk to them face to face. Take a look at RBI, Woodmaster, Woodfast, Delta, Jet, Grizzly and Belsaw.