Lavender is not a good plant for humid conditions like you might have in Georgia. The best way to have success is to plant in a very fast draining area in full sun, you might want to add sand and gravel to your planting hole to improve drainage. Some large rocks might help or planting close to a sidewalk or foundation with a southern exposure, but mainly keep the plants in a very open area to help with air circulation with no other crowding plants. People in humid conditions are advised to try out different spots until hopefully they find a place with conditions that work. As far as successfully growing several types or many plants, you might have to forget that idea. Don't ever water the crown, you will rot out the plant.

They do germinate easily from seed. I don't have too much luck here with lavender. I can usually only get a couple seasons or so from a plant.

Walker's low self sows all over the place, but they are easily removed. I sheared it back after blooming to keep it tidy and so it would re-bloom. Shear back in fall to prevent over seeding. I would love to give you seeds, but unfortunately, those plants were in my last home's garden.