Do you have a budget in mind?
With larger vessels, you are going to need to do either a three-tier gravity system to move the water and wort around or a single tier system with a couple pumps and all of the associated fittings.
Also, how do you want to heat up you liquids? Propane burners, RIMS, HERMS?
Again, there are dozens of ways to configure a three-vessel system. Post your budget or what level of automation you have in mind, and we can give more help. Also, are you a handy DYIer, or do you envision a system that comes pre-built with instructions and the whole shibang? DYI is always less expensive, but always more work, obviously! Something like a Sabco Brew Magic is plug and play, but can easily cost $8000-10000 with all of the available options.
You may also want to go ahead and start researching RIMS and HERMS systems in the Electric Brewing and DYI brewing forums here on HBT. There are also several threads in the Home Brewing Photo Forum that are dedicated to people's three tier and single tier configurations.
Find what you like, and I promise you there is already a thread on board detailing the necessary parts to build it or how to order it!