I don't think there are any ways to make yourself not allergic to cats, but I have heard that allergy shots can be pretty effective in controlling the allergy, but you have to get them weekly as I recall.
For me, I just make sure we keep the apartment really clean, we've got a short-haired cat who we bath regularily (he doesn't really like that ), and we vacuum all the time to try and reduce the dander. I also bought these wipes at pet smart that are meant to "bath" the cat and reduce allergies...don't really know if they work but I figure they can't hurt.
Other than that, I think you just have to try it and see how it goes! I would definately go with a short-haired cat though so at least you'll have less hair to deal with