I urge you all to be extremely cautious when choosing co-sleeper set-ups or cribs for your babies. I was also considering the Arm's Reach co-sleeper for my baby, but it is made in China from polyester fabrics, and even the "organic" mattress is made in China and comes packaged in plastic that is highly toxic. We are now planning to side-car our wrought iron crib with a yet-to-be-purchased organic mattress. If you do this also, make sure you use safe materials, unlike the website posted above that recommends high density foam and plywood.
Anything with plastic, vinyl, plywood (especially!), foam (especially!), or polyester should be NOWHERE near your baby's sleeping space. All of these materials emit highly toxic volatile organic compounds (VOC's) that are very dangerous to a young infant's developing lungs. Research has linked these compounds and materials to asthma and breathing difficulties in infants, and animal studies have also demonstrated that these compounds cause cancer and other problems. Other major sources of these indoor air pollutants are paint and carpet.
A really good book on keeping your baby's toxin load as low as possible is The Complete Organic Pregnancy by Deidre Dolan and Alexandra Zissu.
If you can't afford organic mattresses, cribs, co-sleepers, etc., the next best thing is to find something used that has been around for at least a few years. Most of the toxins from cribs, mattress, foam, etc. will off-gas in the first few years, so they become less toxic after they have been airing out for a long time.
If you are purchasing new items, look for those that are Greenguard certified as safe for children. At present, the only cribs that have certification are made by Q Collection and Young America.
Here are some articles that may be helpful resources: