Probably your best bet is some cheap ones from Ebay. Or, you can do what I have been doing which is maintain a shopping list. Its disturbing how fast I can put together an order that's worth paying shipping for. Another alternative could be to salvage some female headers from old electronics. Careful not to melt the plastic part too much...and stay away from salvaging things with CRTs. Safety issue. There's lots of posts here regarding salvaging parts.