Hi Mark! My first thought is that you need to get busy on doing an in depth market study. I've seen so many businesses (of all kinds) fail because this very essential step was overlooked.

Are you going to grow in the field or in containers? Will the former grower sell you his customer list?

I'd do the market study first, and then worry about soil and water tests later.

I agree with rhizo, the worlds best grower will fail in business if he does not have a market for his plants. I was in business for 35 years, and needed constant reminding that I was in business to make a PROFIT, no matter how much I enjoyed what I was doing. Al

Don't forget to check out the (burgeoning) bonsai market, as both species you mentioned are popular.

You are either a small specialty grower doing mail order, or you are growing on contract for a corporation like Altman's, trying not to go bankrupt. There's not a lot left in between. Another niche is being on the edge of a city rapidly growing in population, providing shrubs to new homeowners. Your retirement fund is your growing field; when the city engulfs your property, the value may have risen enough to give you something to live on in your old age. Look for a book by Tony Avent called "So you want to start an nursery". Good read, good warning.