Protected Content PayPal Subscription Set Up

My web site is intended to have paid subscribers to join the community (BuddyPress) and read our blogs.

Although every paid subscriber has the same access rights, there are 3 different auto-pay payment plans (Monthly, Half-yearly and Yearly). So, there will be 3 different 'Pay' Buttons, right?

For setting up the paid membership,

(1) should it be 1 type of membership with 3 different Pay Buttons, or

(2) should it be 3 types of memberships and each having their own Pay Button?

Finally, where can I find the IPN settings from PayPal? The current PayPal user interface is very different from that shown in the Instructions. I really have no clue of where to set the IPN thing in PayPal.