Wanstalls has a $3600 fusion.
On the less expensive end (Philippines), I Run Guns usually has a few long slides from Iver Johnson, Rock Island Armory (RIA) or Metroarms but doesn't look like any in stock at the moment. Stock changes quickly though.
There are a few more (and cheaper) long slide options if you go the 10mm route (a 1911 longslide should be 10mm ;-)