All mods have been updated for 1.2.5. You can find them at the links provided or search for the Technic Pack. I'll be updating the challenge a bit since there seems to be more interest. I'm open to suggestions for additional mods or rule changes.
I've removed the need for running water and bathrooms in buildings, as they didn't really serve a purpose. The outhouse stays, I like the outhouse.
I've given a grace period before the earthquake affects you, for those that don't stockpile iron. I've also added a seventh stage, which is random challenges associated with different mods.
Before You Begin
To establish a modern feel, this challenge is heavily reliant on mods. If you are unable or unwilling to use mods, this challenge probably isn't for you.
Arrrg's Mine Craft Overhaul This is a great mod compilation containing the above mods plus many more.
Pretty much anything you want that doesn't break the challenge for you. I'm not using Equivalent Exchange for a reason. It's great, but it's pretty unbalanced when combined with other mods.
Some that I use:
RedPower - Huge mod, but, I mainly use it just to simplify redstone.
Not Enough Items - Great for recipes so you don't need to check wikis every few minutes.
Forestry - This adds many automated farms and makes IndustrialCraft and BuildCraft play well together.
Better Dungeons - Adds great places to explore with new bosses and valuable treasures.
I challenge you to build a modern city. Throw away your old Minecraft habits and join the 21st century.
General Rules Always in effect
Stage 1: A New Land
Stage 2: Building Begins
Stage 3: Promising Future
Stage 4: Earthquake!
Stage 5: Civilization
Stage 6: A Modern City
Stage 7: Mod Mastery
Industrial Craft 2 Wiki