I just purchased a Droid 3, and I want 4.2 for it with the Motorola theme. Can someone help me? I use mac and I am a total Noob when it comes to android
I think that the only JB ROMs for the Droid 3 are "stock" ROMs like CM10.2 or AOKP. There is nothing like a stock Bionic JB ROM for the Droid 3 at the moment. Even the CM and AOKP ROMs are feature incomplete - no cameras; issues with audio; perhaps issues with Bluetooth.
Easy - the Bionic has 1 GB of RAM, the D3 has 512 MB of RAM, and that wasn't enough to get the D3 to run ICS with full capabilities (as Motorola and Verizon wanted it configured) well.