Conditional Load Balancing -Transparent proxy

Hi guys
I have connection to 2 isp at this moment and probably another two later…

  • how to set the web-proxy to download simultanously from two ISP for loading one webpage (multisession for each element) ? if mt cannot do that, is it possible to do so with squid?
  • how to setup session load-balancing over these two links?
  • how to define speed per ISP to drive other users from second link (for example of one userA is star to download 100kbyte from link A, pass userB to Link B)
  • how to check which user is ported to which link?

I tried to follow http://www.mikrotik.com/docs/ros/2.8/appex/scripting1.content#11.2.4

but I dont know how to setup SRC-NAT… and how to setup dynamic -ststic routing for website that are hosted on each one of these two ISP…

thanks