What brand/make/model of AIR PURIFIER should I buy and where besides AMAZON.COM?

I recently moved and I suffer from allergies. I was wondering what kind or Air Purifier I should buy. I have seen the ION BREEZE machines, but wonder if those work the same as a HEPA air filter, say from Target or WAL-MART, etc. I want something for my bedroom area only when I sleep at night and something quiet, not noisy. I plan on having a baby too soon, so would like something for them as well. I live in Arizona, so the air here sometimes gets really dirty and dry during the summers (106 heat, bus smog, dust mites, car exhaust, dust storms don't go together! LOL). I just feel safer knowing my air is somewhat gettign cleaned and I am getting a good nights rest. I have seen these machines (various types) in my friends homes and they work really good. One them smokes in his house and his machine sucks the smoke right up out of the air. No residue on the furniture and smells. HELP PLEASE! LOL Just Kdding! I have looked an amazon for info. Just looking for suggestions! :)