Multiple ADSL internet connections one pc one lan

Hello

I have the following situation

I........isp1 (192.168.1.1) ---------->eth0 |-------------------|...................................internal Lan

N.................................................................|..........................|

T........isp2 (192.168.2.1)---------->eth1 |...........................|.............................................------10.1.1.2

E ................................................................| ubuntu PC...... |--------> eth4 10.1.1.1

R ..... isp3 (192.168.3.1)--------->eth2 |.......................... |............................................-----10.1.1.3 .....

E ............................................................... | ...4 nics ..........|

T........isp4 (192.168.4.1)---------->eth3 |--------------------|

I want to connect my internal lan pc's (about 30-40 of them) via my ubuntu router (4 network cards) and to be able to bond or- aggregate or manage or (anything else anyway to use) the 3 or 4 internet connections. The ip's 192.168.1.1, 2.1, 3.1, 4.1 are from the ADSL routers witch are the gateways for 4 internet connections with the same ISP. I want my internal lan to has ip 10.xx.xx.xx

I have done the router with 1 internet connection with ubuntu 7.10 server and iptables.....

I have read the following guides with no success .....

http://www.netlife.co.za/content/view/12/34/

http://www.linux.com/archive/feature/113988

http://www.michaelbrumm.com/how-to-a...bandwidth.html

http://minez-inspirate.blogspot.com/...ter-using.html

http://www.linuxquestions.org/linux/..._Multiple_DSLs

http://chris.olstrom.com/blog/howto/setup-dual-wan/

Please help .....