- I am a user here just like you but have been hanging around for a long time and have learned much. I don't know the deleted answer but I can RE-answer the same questions.
1. Can I add the new plan under my same login account and have both plans, at least for now.
Yes, both a CDMA & GSM SIM accounts can be 'under' the same email address. (Up to 5 devices max)
2. Is the $20 credit sufficient to have both plans or do I need more of a credit than that.
If both accounts are set to the FREE plan then each one requires a $20 deposit made initially. When the credits dwindle to below $2 then another top-up is required. Each device is treated as a separate account. If one is well endowed with credits and the other constantly uses more data, top-ups will be frequent on just that one account.