Cisco WAN :: 3845 - How To Create Multilink Interface And Assign IP

I have a question regarding mlppp and bonding mpls T1 circuits.   For the longest time we have been able to get by on one T1 circuit coming into our 3845 router. Well this T1 has now become congested and they are wanting to add bandwidth to this T1.   We connect to the phone company via an MPLS T1 currently. So now it appears as though we are going to purchase another MPLS T1 circuit and bond the two T1's together. The way our network is currently set up, we utilize the same AS number on all of our remote routers regardless of location.  Keep in mind I don't have any sort of mlppp set up at this moment, so unfortunately I can't post any configs.  I'm just questioning the design portion and how to go about doing this.
 
Here is where my dilemma begins........
 
For every MPLS circuit we order on the remote end, we specifiy an IP for the remote router itself and one for the provider to assign to their equipment (the bgp neighbor statements).   Now granted i'm no BGP extraordinaire, not even a novice really, but I don't understand how I am going to bring two T1 circuits into the same router (basically with 2 pairs of IP's).   In order to bond the two T1's together, i'll need to create a multilink interface and assign an IP to that, but yet I still have 2 SETS of ip addresses. And if that isn't enough of a dilemma, I also need to spedify a neighbor statement in order for my AS to bind to the adjacent provider AS, but yet I have two IP addresses for that as well.