Welcome to TPT!
I've got an aunt and uncle that live in Canton, I go there every other Thanksgiving...
I personally would do without the UG filter; the plant roots will grow down into the plates and cut off the water circulation. That could get nasty and will definitely make replanting very difficult if not impossible down the road.
You'll probably also need to get more filtration in the long run that just the Emperor 400, depending on how heavily you plant the tank. Planted tanks need good water circulation as the plants really interfere with water movement otherwise. Most ppl use canister filters on a tank your size, but you could also use some powerheads with sponge prefilters if you'd prefer. I'm personally running an AquaClear 110 HOB paired with a Rena XP2 canister on my 90gal lowlight. Not enough circulation will lead to nutrient buildups and algae blooms.
Using straight gravel it is likely you will need to fertilize. Depends on your plants and bioload, however. Fert tabs might be sufficient if you're looking for very low maintenance; they typically only need replacing every 3-6 months. I'm using a mostly Fluorite substrate, fert tabs, and Flourish comprehensive to supply trace.
Your lighting sounds good; what bulbs do you have in there? Bulbs rated between 5000-10000 kelvins are generally needed to support FW plant growth.
EDIT ninja'd by sick lid LOL