Yes, probably Dr. Pitcairn or Dr. Goldstein's would be better picks, as they go into more detail on specific issues. I'm not a home right now so can't check if any have information on fear/anxiety but I'd guess they do.
Flower essences may work well, Rescue Remedy is the standard for trauma/shock and good to have on hand, and some of the essences in RR are for fear and panic. Off the top of my head, Mimulus for known fears might also be something to consider. Here's a link for more information on the different essences - click on the name for more detail:
http://www.bachcentre.com/centre/remedies.htm
You might want to open a discussion on the health or behavior forums, Susan Fulcher on the boards is well-versed in flower essences and other members have used them as well. A search may pull up other discussions on fear of the vet, I'm vaguely sure we've had one before.
Conditioning may also help, giving lots of super-yummy treats as soon as the vet clinic is in view (or whenever he starts exhibiting fear), taking small steps and jackpotting for even the slightest bit of progress.