http://cgi.ebay.ca/ws/eBayISAPI.dll?...394792317&rd=1
Look there for cheap RO/DI units. The guy ships out of Vancouver but it seems like he is having problems getting the tanks in. I am sure it will clear up soon.
About the wastewater, someone with more expertise will have to let you know!
Steve
*Willow is quicker then I*