Asthma and Owning Kitties (Ideas Please)

Wondering if anyone out there has some suggestions for us.
My brother and his wife recently rescued 2 abandoned kittens. My bro is a
real kitty guy and a great pet owner, but he has always had asthma. He had
a fairly severe attack the other night and had to go to the ER. The doctor
was pretty adamant about him getting rid of the kittens. Cautioned him that
Asthma attacks are *serious* and that he could die from one (which sent his
new bride into a panic). Of course Tony wants to try to keep the kittens.
I told him about AllerPet, but does anyone have any other suggestions for
him?
I would love to see him be able to keep the kitties, but not if it puts him
in danger!
Also, he's new to the area (moved to Kansas City from Pheonix, Az) and its
ragweed season now. Could it be the ragweed instead of the kittens? He only
had a few sniffles here at our place a couple weeks ago, and we have 4 dogs
and (yikes!) 6 kitties.