I don't know much about nova-network or your Apache requirements. This answer is just for the last part of your question about neutron.

With Havana I was able to create a port and add two fixed_ips from the same subnet to it. Then pass this port to nova boot. In the instance I had to add the second IP to eth0 manually as the dhcp client didn't. Then I was able to create and associate a floating IP for each internal IP.

See http://paste.openstack.org/show/49514/

Update: actually it would be easier just to do this, and let Neutron allocate the IPs:

neutron port-create net1 \
    --fixed-ip subnet_id=2a9da468-73e0-4418-93de-69e00887b0ee \
    --fixed-ip subnet_id=2a9da468-73e0-4418-93de-69e00887b0ee

Also there is another way here.

It is possible to add an instance to multiple networks. This would give the instance multiple fixed addresses to which you can assign floating IP addresses. This seems to be the only way, although it requires you to set up routers and subnets for each new network.

That seems to be the only way to get multiple fixed IP addresses straight from Horizon. There might another way using nova/neutron CLI. You can try using quantum floatingip-associate.

It takes two arguments:

positional arguments:
  FLOATINGIP_ID         ID of the floating IP to associate
  PORT                  ID or name of the port to be associated with the
                        floatingip

So you would put the floating IP ID as a first argument (find it first by quantum floatingip-list) and the port as second (find it with quantum port-list").