I second Neil's recommendation of Sams. They are prompt and extremely easy to deal with. I have found communication to be a problem when trying to secure visas. That will not be an issue with Sams. I know Neil's preference might be geographically biased (as Neil and Sams are both based in Houston
) but Sams has satellite offices in L.A. and Washington D.C. to help them expedite certain processes. Happy travelling and we look forward to a complete post-trip review.