Personally I think diversity is good on a broad scale and then whatever you prefer to specilize in would help a lot, say for example you specialize in strawberries and figs, then I would try to go really in depth in both of those things and have a broad array of seeds of both of those that people might not grow, that way when people are looking for something strawberry or fig related you might be one of the only people around with it. It would be nice if somebody got a database together and we all started doing that. It would be a great way to get top notch flowers, bulbs, and seeds by trading like the seeds swaps but exactly what your looking for.