All vets have some rabbit experience, its apart of their training, most did it "way back in the day", they usually just see dogs and cats because its whats drilled into them, its whats comfortable.
For spays... a rabbit is the same as a cat/dog. Neuters are slightly because bunnys can suck their parts in, different but not difficult.
The only thing really difficult about neutering/spaying a rabbit is their size, alot of vets will refuse to do cats and dogs under 6-7 months so a small bunny might be difficult, however some vets work with breeders and will spay/neuter 8week old kittens before they go to their new homes. Ask vets if they do that, those are your best bet since they have more experience dealing with itty bitty parts.
There isnt anything special pre-med wise for bunnys, some vets will give them pre-meds, catheter them, then inject anesthetic before putting them on the gas, others will just mask them down with just gas. Both methods are totally acceptable and safe. Rabbits dont get tubed.
Were not looking for rabbit savvy diagnositcs here, just somebody who can safely do the procedure.
Have a read through here
http://rabbitsonline.net/view_topic.php?id=12040&forum_id=10
Great articles and photos and what to look for in a vet.