Yeah with Aqadvisor I generally keep a tank "stocked" at 70% or less so that I have wriggle room if anything goes wrong. Also keeping the filtration 100% and over is key, over filtering is a good thing! And you can always baffle your filters as well.
I have plants, lots and lots of plants and I love them. I will never go back to silk plants just for the mere fact that with live plants, they grow and make more, silk plants don't do that lol. 26 watts would be fine. Basically what you want to look for is a light that reaches all the way to the bottom of your tank so that all plants get a nice equal light. It used to be a 2 watt per gallon rule but that has been since debunked :)
Some good plants would be: Anacharis (although is generally a cold water plant, you can acclimate it to a higher temperature), Anubias (slow growing but a great plant, hard to kill), Java Ferns (I love all of mine and they're supposed to be slow growers but I get a new sprout every week), Water Sprite (good floating plant and grows very fast, all my Betta's sleep in theirs), Cabomda (high light plant, but generally fast growing), Hornwort (can float or be planted, fast grower), Any Java Moss would be good too, and Water Wisteria (not Hygrophilia Difformis, there are two different kinds of water wisteria, the one I have is from Petco/Petsmart from the little tubes)
With plants, with the correct lighting you shouldn't need to many fertilizers but I use API's LeafZone and it works fairly well, I haven't had too much die-off which is good. Once a plant leaf starts to rot you should take that rotting part out so it doesn't bring the ammonia up in your tank :)
Leopards: 1:4 Hawkeye, Luna, Astrael, Dorian, Cullen