Park makes some prebuilt kits, might be worth taking a look at that route. Generally buying a kit lowers the cost vs buying the tools individually, plus Park makes some nice tools.

Home Mechanic Starter Kit: http://www.parktool.com/product/home...ic-starter-kit $70-85
Advanced Kit http://www.parktool.com/product/adva...hanic-tool-kit $225-235
Add to either of those a torque wrench calibrated in in/lbs and a copy of Zinn and the Art of Road Bike Maintenance. Also Grease, chain lube, citrus cleaner, etc.