Some of the more popular American based dealers are BBTS.com TFsource.com In the UK there's Kapow-toys.com Others will chime in with other dealers. If you order from outside the UK, you may pay import tax.
Oh ya Kapow toys, he's also a TFW member. from what I heard of him here, it's mostly positive feedback. the convenient thing is just can just PM him directly for any queries. His TFW nick is Red Leader: Red leader's Profile - TFW2005 - The 2005 Boards
I cannot recommend Kapow Toys strongly enough. Red Leader's a top guy, I buy almost all my stuff from him now.