BIS is BIS, all i did when i bought my bold at the att store was drop in my SIM out of my Curve and switch the PIN in BIS.

Theres no 3g BB plan, or regular BB plan. All you need is a SIM card with 3g on it, and you are good to go.

Ive had the same SIM card since my Treo, then 8525, then my Curve.