Looking for a design best practice, and a little help,

Basically my design looks like this

                                   Internet

                                        |

                                     2821               (Single ISP w/BGP failover to redundant site)

                                   /         \

                                4948    4948        (Inet/MPLS Switch)

                                   |           |

                                ASA  --- ASA       (5520's Failover Pair (Advert BGP AS from here))           

                                    |           | 

                                 6506 --- 6506       (Core (VS-SUP720-10G)           

The 4948's also have a pair of 2821's that are from 2 seperate carriers provideing MPLS connections to the other site/corp office off a single vlan to both switches (Load balanced with OSPF, and Connected to the ASA's via "DMZ_MPLS")

Here is my issue, as of 8.x the ASA's dont support etherchannel of 2 or more interfaces together, so, if i connect the 4948's together with a "Uplink" port that's layer 2, and set the internet router to use a BVI interface that uses both G0/0 & G0/1, aren't I going to run into a "Non-Mac-Flooding" issue?

Can i create a "Layer 3 Interface on both 4948's and use that for a "Uplink" to ensure multi-path?

I realize that i am useing only a single internet connection, but would like to have full redundancy up to that single point of failure, as if the i-net router fails, bgp fails over to the secondary site.