I am running a SunSun 304B on my 40 gallon tank and an Odyssea 36 inch light. I think its 78W? Not sure its 2 T5HO bulbs.
For heaters I have my inline but I made it. A lot cheaper than the Hydor 200 or 300 W heaters. Check my build if you want to see how. It's customizable with the type of heater you use and the PVC parts run less than 10 bucks. maybe 15 if you are high rolling haha
Easy plants off the top of my head are pennywort and sunset hygro. They grow medium high and look nice.