The concern I would have is over filtration. Planted tanks filter themselves. The only reason for a "filter" in a planted tank is to gently move the water (or to move it in a stronger current if you have fish requiring currents) through a sponge, pad and media (as in a canister) to keep the water "clear." The plants keep it "clean." Two different things.
Second issue is what fish will be in the tank. Filtration should be geared to the fish, some like currents, some definitely do not--cardinal tetras, indeed the majority of tetras do not fare well with strong water flow because it is not part of their habitat, similarly gourami, rasbora, angels...all these come from very quiet scarcely-moving streams and oxbow lakes and marshes, depending which species.
If the tank is pulled down (i.e., not already set up and being converted that way) I would remove the UG filter and use the canister. Canisters are good filters in planted aquaria. UG filters are do-able, but not the preference. As for the substrate, small-grain gravel about 1-3mm size is best both for holding the plants, allowing good root growth, and supporting the very important colony of aerobic and anaerobic bacteria that are essential at the plant roots.
I am also not a fan of potting plants in aquaria. Substrate-rooted plants that have extensive root systems such as swords and crypts, which are two of the mainstay plant genera, are much better in the open substrate. They have very extensive root systems, and they are heavy feeders. The root systems of some of my larger swords extend out more than a foot in all directions from the plant, and down through 4-6 inches of gravel. If you want a success, it is best to provide close to what the plants can most benefit from; it will be more successful and you will be happier with the result--as will the fishies.
You might want to give Part 3 of my stickied series on natural planted aquaria a read, it covers filtration and explains the reason for what I've said above: http://www.tropicalfishkeeping.com/a...um-part-34858/
The whole 4-part series is at the head of the Aquarium Plants section of the forum.