mgb
1. "elaborate" solution
what about 2 clsasses and VLAN on switch's?
let's say
you need that PC1,2,...5 need to have IP from DHCP 1 (your main router or your 2003 server) with default gateway ADSL2
and
PC6,7.... need to have access to gateway SME through ADSL1
you put this computers in different VLAN's and in each VLAN you put separate DHCP (one SME box) with different gaeway, and you made both routers (SME box one of them) in the same third VLAN with routing policies between them
2. "poor man solution"
you put only one DHCP server which give you access to the "normal" gateway
on the computers where you'll need gateway 2 (PC6,7....)
implement one small script/batch program load at boot doing this
route delete default
route add default newGW
(this is not the real code - it depends where you want to implement it in windows is witn 0.0.0.0...)