When I was thinking of moving to Florida I was researching the same thing. Seemed to me using substrates from the pet store would have been easier to set up but would cause problems. Had decided sticking with dirt and topping with sand would be less stressful for fish.
In my tanks I put reptile coconut bark on the bottom. For it prevents smelly air pocket from developing. Then mix some potting soil and top soil. Next tank using Hydroponics potting soil and Scott's top soil. For sand I found river sand from landscaper needs very little rinsing. Mostly just sift the larger pieces out. Found after a year the ferts peat out thus added DIY root tabs to established tank.
On 1 thread read 1 saved the mulm from the bottom of the tank when emptying for seeding the substrate. Many I have read just seed the filter with old media.