If you are intent on using a prototype board (I assume you mean something like a breadboard or perfboard?), you have a few options. PLCC sockets with through-hole leads can be found, and this is certainly a viable option...especially if you are not experienced in soldering fine-pitch parts, as they are easy to damage! If you are confident in soldering, but simply want the part broken out to a larger pitch, try this company: http://www.schmartboard.com/ I have never used their products, but they appear to make what you would need if you wanted to break out, say, a TQFP package.
But really, as has already been suggested, look for a good dev kit...A basic one will not be expensive, most include some peripherals, and some even have a small prototyping area attached. Many also bring out a large proportion of the device pins to standard 0.100" pin headers.
And, if you want something more custom than a standard dev board, it is not that expensive to fab a custom PCB. 2-4 layer boards can be made for less than $100, and some companies even have free layout tools. (I have worked with ExpressPCB
http://www.expresspcb.com and Advanced Circuits
http://4pcb.com/ and I am sure there are others....I personally prefer advanced circuits, although beware that you should design above their advertised minimum clearances....)
Good luck and have fun!