If you want to build a lamp that the color mix changes by it's self and don't really want to do anything else with it, then the BlinkM MaxM is the right choice. They can be programmed and then unhooked from the Arduino to run on their own. It looks like you have to use a controller, like an Arduino, etc., to control more than one at a time if you want to manually very the color mix. If I am wrong, someone please let me know.
If you want to be able to have multiple modules that you are going to manually change the color mix with potentiometers then I would go for the MegaBright. You leave it hooked up to an Arduino and can control them individually or as a group.
*** You can do the same thing with the BlinkM MaxMs but you are paying for a controller built into each one but not using them to their capabilities. ***
The data sheets state the following:
BlinkM has 8000mcd of light per LED. That"s 24,000mcd total. :'(
BlinkM MaxM has 445,000mcd of light total? Is this right? That would be almost 145,000mcd per LED. :o
MegaBright has ~35,000mcd per LED. That's 105,000mcd total. ;D
For the price, I would use the MegaBrights and control them via Arduino. 2 or 3 should be all you need for a shoebox. :P