Daniel,

Maybe patience isn't your strongest point? I've imported OBJ files as large as 250 MB without problem. Coffee and fags make waiting more pleasant.
Then, there's always the XMX trick to increase memory.
Also, the way you organise your work can make design life easier or harder. If you install the CopyAsNewFurniture plug-in (pdf), you don't need to ex/import an OBJ file.

Hans