This company offers a beatiful (or so the photos imply) model of the Wuppertal monorail in HO scale. It's made in Germany and it's not cheap, but take a look at how nice this looks!
http://www.hielscher-dampfmodelle.d...ategory_id=10&option=com_virtuemart&Itemid=38
The “Wuppertal Overhead Railway” model series was developed and constructed by the Lutz Hielscher company to commemorate the 100th anniversary of the railway in Autumn of 2001.
Because of the precise scale H0 the overhead railway can be integrated perfectly into your existing model railway.
http://www.hielscher-dampfmodelle.d...ategory_id=10&option=com_virtuemart&Itemid=38