Thank you for the advice and help. Can you tell me how gravel with root tabs work exactly?
Regular ol' gravel or sand is inert, with poor nutrient storing abilities, so we usually suppliant the substrate with what is known as "root tabs". Basically, they are dry fertilizer in a slow release/stable configuration that we place near plants like swords/crypts/apongetons/crinum/lily's etc etc to give them nutrients. These plants are very good as uptaking nutrients via their roots.
How deep of a bed do I need?
Anything from 1"-3" start off with 1" up front, and gradually increase the depth as you move towards the back of the tank.
Does that work as well as the other substrates?
In my opinion, planted tank substrates (excluding ADA aqua soil or similar substrates) are a bit of am overpriced gimmick. They grow plants just fine, no issues there, but for the price you can invest in better lighting, CO2, fertilizers etc. and use plain sand or gravel with terrific results. Plus, plain substrates are easy to keep clean and come in every colour/texture you want. Check out black diamond brand blasting sand and pool filter sand
What size gravel is best?
Any size works, but generally large "pea" gravel is too big. Stick to less than 1/4" diameter.
I have heard about a soil tank with gravel on top. Is that better than just plain gravel or is it just a matter of preference? What type of soil is used?
Yes and no. Soil or "dirted" tanks can grow plants very very well, but they can turn into a very very big headache as well. New soil released ammonia and can stain the water, plus everything turns into a huge mess when you break the gravel or sand cap. Eventually, you are going to have to fertilize anyway as the dirt can only supply nutrients for so long.
Any soil made with organic material only is generally used. The most popular being Miracle Grow Organic Choice Potting Mix. There are steps in preparing it, make sure to follow a few of them to limit chances of a disaster if you go this route.
Soil is capped with whatever material suites you, sand or gravel usually
I have done some research and this is what I am looking at now. I am looking for opinions and advice if possible. These are the plants I am interested in:
Anubias
Amazon sword
Water wisteria
Java fern
Dwarf lily
Anacharis
Dwarf sagittaria
Any of these plants will do well in low-medium light, with or without a planted tank substrate. Just invest in some good fertilizers and you should be fine. Swords, lily and sagitteria will like root tabs, anubias, wisteria, java fern and anacharis will like water column fertilizers like Thrive or aquarium Co'ops all in one mix.
Thanks for your help and thoughts.