LARTC - Nov 2005 - Combining DSL lines

I am looking for a solution to take 4 or more ADSL lines with PPPoE and 
a Static IP and then have my Local network behind them.

I was reviewing http://lartc.org/howto/lartc.rpdb.multiple-links.html 
and it looks like a good solution.

How can the document be modified to do NAT from the local network?  I 
would need the local network to be NATed to the WAN. 

How can I set it up so that the external interfaces login via PPPoE?