Black MacBooks run faster than white ones.
Um....honestly, just get the colour you want.
The MBPs have the least problems, but only because the design is old now and they've fixed all the major flaws.
And as I've been here for "awhile", I personally believe the 17" MacBook Pro is the least problematic. It's really a design issue related to how much stuff they try to cram into a small volume of space. A 17" makes the least compromises.
Also, I believe the 17" MBP to be most reliable because you almost never hear of a problem with them here. I know there are fewer 17" MBPs sold than 15" MBPs or MacBooks, but even taking that into account, the 17" MBPs still get far less complaints.