It really depends on your allergy, everyone is different. I would definitely recommend spending extended lengths of time with cats before committing to one yourself. With my own two, I still get sneezy, if I'm forgetful and put fingers in my eyes they puff up and go bloodshot, I sneeze most mornings until I take a tablet. It's all about management and putting up with it because I am so passionate about cats.
I have built up a tolerance to my two but it gets much worse with new cats and I have to make sure I take drugs with me otherwise it can be hell!
It all comes down to your own level of allergy, your ability to persevere if it's manageable, your body's tolerance to anti-allergy tablets (I've tried a few, some make me drowsy, some don't, some don't work) and whether you are prepared to love with your allergy every day for the life of the cat.