These are decisions to make in consultation with your bankruptcy lawyer.
Read about Chapter 7 Bankruptcy here. It's a discharge, so while there may be some repayment during the process (if you have non-exempt assets), once it's over your credit card debt is wiped out.
I don't know what you mean by the "difference of taxes". I assume you mean, will you receive 1099-C's for the debt that is discharged. You should not, and if you do you can object (see IRS Form 982) - bankruptcy is not a "write off", and you don't get taxed on the discharged amount.

