I moved to AG with BIAB and then made a 3 tier gravity system using converted kegs. Once I started making 5 gallon batches I thought "I could make 10 gallons for almost the same amount of time" so with that in mind I built a system that could easily handle 10+ gallon batches and found the time difference to be 30-45 mins more than a 5 gallon batch.
I did as was already suggested and looked at pics of brew rigs here and in Google so I could get an idea of what I wanted to do achieve.
As for the kegs, I bought kettle valves, and the false bottom for the mash tun from my LHBS and bought the thermometers and sight glass kits from Brewhardware and made my own dip tubes.
Here is my setup, hope this helps.
Oh 1 more thing I found that my 3/8 x 25' wort chiller didn't cut it anymore so I bought a 1/2 x 50' from Coppertubingsales and love it.