Here in my place, there is an over-the-counter transaction for purchasing large volumes of BTC. But I prefer a peer-to-peer transaction. That would be the best choice. That would be much safer in terms of protecting your identity. I guess you are avoiding doing the purchase through exchanges for the same purpose. 

Here: https://bitcointalk.org/index.php?board=53.0. This is the section where you might want to post your terms and offer.