Set address as default billing address

Hi,

I am working on a site to send gifts. In general billing address and shipping address will NOT be the same.

I would like to add shipping and billing address at the same time. Currently I have to add an address, then select change address, then enter new address, then select change address again, and then select one address as billing and other as shipping... very complicated to users.

Also I would like to set an address as default billing address, so in the future all orders will be billed to that address.

regards,
Luis