Here's the backstory. It's been 25+ years since I last did a piece and aside from small (non-artistic) projects, have not painted anything big. I have a spot where I want to paint this sunflower in memory of my son who passed away. The idea came from my youngest singing the song after his brother passed away and sunflowers have been my family's connection. I have about 10-12 feet tall and 60+ feet wide of blank wall to play with. I'm having a hard time trying to figure out what colors and how many cans I will need. I even thought about going the grid route, even though everything I have never done has been free-hand with a rough sketch. Any input, advice etc. would be appreciated.