There's only one state that I know of in the US that differentiates between juice and cider. They say juice is filtered clear, cider is cloudy. You don't have to filter to get clear, a little pectic enzyme will clear cider quickly but there's a lot of waste and you are removing some of the healthy stuff (the pectin for one). Europe has the difference between juice and cider as unfermented and fermented. Fermented is "hard cider" in the US. So here it's up to you what you call it. To me "better" for applesauce is a little tart and cooks down easy. My niece likes my Arkansas Black sauce for taste but you could cook them forever and they'd never turn to sauce without a stick blender. She hates tart which is why she started giving me the apples from her old tree. So flavor is in the eye of the beholder. I think any apple that softens readily in storage would be a good candidate for cooking down easily. I've done Cortland (stays white as sauce) and McIntosh and they do good. Yellow Transparent and Lodi are said to be good sauce apples.

One factor that will have a significant impact on taste and perhaps texture is how you plan to preserve it. I assume you will be using some type of canning and pasteurizing. It will need to either be sufficiently acidic or brought to a relatively high temperature and pressure. Oxidation during the processing may also be a concern with respect to color and perhaps flavor. You said you are more interested in the actual production than in the legalities, but those things may be very highly related. The regulations may require specific production practices. It could be frustrating to come up with a plan for production only to learn that it cannot legally be followed. I'd personally want at least a outline of the regulations before making any investment, and by investment I don't just mean money. Aside from those comments, I'd think that the varieties of apples that you use will have as big an effect as anything on the taste of the sauce.

I didn't bother with the seeds- it turned out wonderful! The orange and lemon zest was a great twist to both the batch with and without the raspberries. I will definitely add that again. My "poop shoot" on my food mill broke- all the little plastic tabs snapped off. It was inevitable. My husband fixed a hose clamp over it and it worked for now. I guess I'll have to order another piece.

I have the same problem with almost all my canning, I can't seem to get the temps they recommend when I use my canning thermometer. I think that these thermometers are just way off. I have ruined a few things by trusting my thermometer instead of what it looks like. I got strawberry taffy once trying to get my jam to get to the right temperature, and I ruined a batch of peach jam. I have also overcooked meat on several occasions waiting for it to reach the prescribed temperature. I would like to get something higher end in the thermometer department but sadly I can't afford it. I don't do enough canning to worry about it, but if something is actually boiling, it does have to actually be at a certain temperature in order for that to happen. One of the issues is knowing if you have to adjust due to your altitude, that will affect temp. Not sure how much boiling temps can waiver, would be an interesting experiment.