In hotter regions keeping your corms dry when dormant is not all that important, given that you have given them good drainage to begin with. Yes, I know the books say they demand to be totally dry when dormant, but I have found this not to hold true. But, in cooler climates, regardless of your good drainage I would play it safe and keep the corms dry when dormant. Plants if over watered can rot. Again, by growing from seed, and finding more than just one source, you are allowing for genetic diversity in what you grow.
Nature is very adaptive.
The temptation to buy flowering size bulbs and corms is always with us, even I give in occasionally and buy them. This is not a put down to the nursery trade, far from it, we have good Nurseries world wide, like Kellydale who grow from seed. Also, Hillview Rare Plants in Tasmania, Silverhill Seeds in South Africa and others. But, as technology advances, it is becoming more likely that you could be buying clones of plants that are easy for the grower to handle, or that are quick to come to flower. These may not behave well for you in the garden.