I think ratshack sells some "kits" for this. Or at least they did when I worked there. It would be cheaper to use those than manufacture a PCB. Believe me I know.
Also, used furbies are awesome. There is a lot of documentation on hacking a furby or a talking elmo. probably ebay them really cheap. The speakers arent great but the storage is there, and you can hack the audio output really easily.
Is this the sort of thing you were looking for?