When user checkout, I need a way of presenting a form for the user to choose to collect the items themselves, or for us to ship out the items.
If the user select to collect, then no shipping address is required and the user will be directed to make payment.
If the user select shipping, then the shipping address pane should be presented for the user to fill up ... and the shipping fees be added as a line-item and sent to make payment.

Wondering how I can achieve this? with or without coding is fine. Just need some direction the way to solve this problem.

Any help or suggestion will be greatly appreciated.