Hi Neil, all the hard questions coming now while I'm away from home of course!
I'll give a better
answer in a few days when I have my computer and library but here goes:
Fermented products sounds great if you have access to commercial kitchen. In addition to food incubators most churches, granges, and masonic halls have them and rent them. We have used the culinary prgram of our vocation school to good effect.
For seeds, i'll post a good manual link for processing. Meanwhile, Johnny's, Fedco, and Prairie Moon all buy seed from small growers. In some cases you have a weed already growing with high price seed. PM will sometimes pay for local genotypes even of common things they already have like milkweed and cattails for example.
Herbs are not my area of expertise but I'll post some links. Frontier buys wholesale. Again a study of whats already on site may yield a
medicinal crop.
Finally some easily grown annuals help fill the gap. Culinary herbs for restaurants, cut flowers, etc. i'm big on dried ground cherries - easy to grow, selling for $18/lb as superfood at the moment.
In livestock world broilers seem to be quickest return.
Process regular PC design with extras:
Goal setting including revenue
Site analysis inc desired products and heir suitabilityto site, and gen suitability of site to various crops and livestock,
wood products etc.
Design concept and schematic involves fleshing out scenarios and runnign numbers.
Detailed design adds biz plan.
Great book on this is Planning your Small Farm from smallfarm.org which walks through the schematic phase and looks at
land capability and location, market research and strategies, financing, and enterprise selection. I do a course based on it in MA, it is a great tool. The prequel is Exploring the Small Farm Dream which helps assess tourself and determine if farming as a business is right for you. After Planner try Tilling he Soil Of Opportunity farm biz
class, was helpful to me and many friends.