Before you worry about load balancing, you need to verify that your ISP will allow you to host a web site, let alone a web server.
Then, check your upload speed and traffic limits.
Most ADSL providers do NOT allow hosting.
Beyond the contract, ADSL is NOT a good connection to run even a single web site from.
Like cable, your upload speed is just too slow.
Once you get into SDSL with a high minimum guaranteed bandwidth, and 2 ISPs, you may find other options to be more cost effective and better suited to your needs.
Chas