Hello, and welcome to SD. Sounds like you already did some research on your discus tank, but here are some things I'd caution against:
- What size fish are you planning to get?
- Black is usually a poor discus background/floor color, as the discus will often darken as well. Besides white, medium or light blue is popular. I've also seen some tanks with light tan backgrounds that look sharp.
- You don't need two, 250w heaters. Unless the room is freezing, one will suffice. Two, 100w heaters would be even better.
- Do you have room to age your water? Even "small" changes in pH can be very stressful to fish. Not to mention dissolved gases. A Brute 33 gallon trashcan on a dolly is easy to use and hide when company comes over.