Arduino Due or Mega 2560 for LCD project?

Hi,
I am going overkill on my home LED and appliances controller, and was thinking of adding a touch LCD screen to the project.

However I am not really sure what controller that is the best for this kind of projects and was hoping for some help from the community. My research in the subject so far has ended in a recommendation to go Mega as the 3.3v Logic in Due, but since both the LCD and wireless driver is driven over 3.3v that would not be an issue for me in this project. And the Arduino used will be dedicated tho this task and incased in the wall only leaving the a frame and the LCD visual from the outside. The other part of my research has ended in a "don't use as a first arduino". And since the first version (no LCD) is made from a Arduino UNO I will then have a few UNO to use for experimenting in the future.

Connected to the arduino vill be:

  • 5" LCD with Touch and SD-slot
  • NRF24L01+ 2.4GHz Wireless Transceiver Module
  • I2C RTC AT24C32 DS1307 Real Time Clock Module for arduino (not sure about this an 3.3v logic)
  • Ambient light sensor
  • IR LED
  • a bouncy of LED's (all driven from another processor installed in the lamp) (I2C and wireless).

Timing and memory is of a big importance as one controller will control a few LED modules and the elements in the controller will be mostly pictures as on a smart phone and its icons...

I hope you can help me at i am totally lost at the moment. My biggest concern is that the 84Mhz Due won't work well with the other 8 and 16 Mhz units in the I2C or Wireless line. And as i am planing on 3 controllers I hade the (not so) brilliant idea to build one of each and try what works best, but it feels like a waste of money for nothing if i first can get help here.

Thanks in advance.
JE