I have been looking to purchase an air purifier for my son [still saving up] and this company seems to me to have the best product and price combo.
Don't know what price range you're looking at - the unit described below is listed for $199. You can take a look at the link and maybe contact the company with questions if this seems to be what you're looking for.
Excerpt taken from: http://www.air-zone.com/xt120dorm.html
ďThe Air-Zoneģ XT-120 features a brand new 21st century method of producing ozone.
The permanently mounted ozone elements inside the unit produce pure ozone with no measurable nitrogen oxides that can make some air purifiers dangerous and offensive.
The unit also puts out a sensible amount of negative ions that help scrub the air clean, and cause many floating particles of dust to simply fall to the floor.
Designed for continuous or timed air cleaning & odor control in bedrooms, offices, and similar areas. It features fully variable ozone control, and a built in "Burst" timer that makes it perfect for use in occupied areas.
The XT-120 is perfect for dorm room air purification.ď
For other suggestions you may want to post on the "Oxygen" forum, or take a look at old posts, or search the forum for "air purifier".
As for the heater question, I don't have answers - hopefully someone will have some ideas for you.
Please Note that I have no association whatsoever with this company, I have only been looking into an air purifierfor my son and thought to share my findings.