Advice on new DNA or S3

I have been thinking abt new DNA or S3. I use mainly camera, touchdown(wk email) & FB. What is a better choice?

I have the family plan not the shared everything with 2x unlimited data lines . Dummy line is eligible for upgrade. I would like to get the HTC DNA or S3 by adding data to the dummyline, activate it, deactivate it leaving it back to the dummyline and transfering it to my unlimited line with no penalties.

My question is can I only get the new smartphone via Verizon or can I get it at BB, newegg ($150 with $50 giftcard) , Sams club etc? And if yes, do I tell the workers there to activate, deactivate and activate on my unlimited data line?

Thanks in advance

If you read the "fine print" for places other than Verizon (like BB or Amazon) the phone must be activated on the line the upgrade was used on for 181 days or you must pay a fee which is the discount you originally got. So you would end up paying the full price of the phone if you switch lines before 181 days.
I just did the same trick to keep my unlimited data so I read through all the terms of service to see if I could buy my phone through BB or Amazon. Just go through Verizon and be safe.

Sent from my Galaxy Note 2