For vet visits - Birman aren't known for any specific hereditary problems, though there is some concern among lines for sensitivity to anesthesia, so if you can get blood tests and such done before putting them under, that's best. After World War II the Birman population was decimated, and they had to outcross to other breeds in order to keep them from going extinct. The sensitivity to anesthesia (as well as some undesired show traits like white spots other than on the feet) are thought to possibly have come from this outcrossing in the past.
They're very social cats - most do better with a buddy or two around, so its good you already have other cats. They're also very people cats, but at least my two would rather have me than someone else. They're not always very cuddly (my two rarely sit in my lap) but they will often sit next to me or near me, and love pettings.
As far as activity level goes, they're sort of medium level. They'll have their
"midnight crazy" sessions where they run around like elephants, but of course they have no where near the activity level of a Bengal, say.
Birman as a whole tend to like to play in water, yet another thing my two don't do.
What else can I think of.....as far as looks go, Birmans are suppoesd to have a nice broad Roman nose with a "bump". The trademark feature of Birmans are their white feet - show-marked Birman have "gloves" on their front feet, where the white should end in an even line across the top of the foot. Their back feet should be white from the front, ending in a nice sharp V in the back. These two traits are what most commonly keep a Birman from showing. Their coats also tend to have a goldish cast to them, as if someone misted them in gold.
Random fact - Birman are named for the year they were born in, like some other purebreeds. So Billy was born 3 years ago as a B, Chay is 11 months younger and so was born in a C year, last year was D, so this year's litter is E, I believe. Q and Y years always end up having fun names.
They are just the most gentle, beautiful cats in the world, and I am so blessed to have two of my own after wanting one for three years! I'll let you know if I think of anything else, but check out the online Birman sites - there are some really good ones out there. Be sure to read the legend of the origin of Birmans, its one of my favorite stories!
Official site http://www.birman.org/
CFA site http://www.cfainc.org/breeds/profiles/birman.html
Another good one http://www.birmanbreeder.com/
A great breeder with lots of info on the breed http://www.birman.net/
I know you'll just fall in love with him!