I did an ebay search and found a place like one of these:

http://www.easternmarine.com/14-15-a...iler-Tire-Rim/

http://www.trailerpartsdepot.com/ite...atus=0&Tp=&Bc=

For my mount I got a cheapo one that you can't see behind the covered wheel. It was like this one:

http://www.harborfreight.com/catalog...are+tire+mount

The most important thing is the cover, which I got on ebay. It sits in the sun down here so it has to be covered or it will get destroyed. In fact, my cover is a couple years old and it's destroyed. I need a new one this season. I got a cheapo one and coated it with 303 but 3 seasons is still about it.