If you are interested in playing around and making a budget, I have done the work of organizing my favorite brands and putting together a few spreadsheets that you could use to estimate the overall cost of your project.
Being able to turn lights on and off directly from your phone is not really all that interesting. The power in the technology is that you can orchestrate different lighting combinations using scenes. Scenes allow you to set certain switches to on or off, and if they are dimmable, to a specific brightness level.
I have four total scenes for the indoor common areas of my house. These scenes control the living room, entry, dining room and kitchen… They also control the stairwell and halways. Overall I have over twenty Leviton Z-Wave switches that are connected to the VeraPlus scene controller.
This scene has overhead lights off and lamps at 50% brightness.
This scene has overhead lights at 10% and lamps at 80% brightness.
This scene has overhead lights at 70% and lamps at 80% brightness.
No picture needed. This is the scene that we press right before we go to bed at night.