Depending on what you're looking for there's a lot of things on the market. A lot of the time, as long as the miniatures is the right
size, the scale doesn't matter.
The
Shattered Void miniatures from White Dragon are rather pretty, although I'm not sure exactly what's for sale at present (I bought one or two of their ships at Salute a few years back)
Ground Zero Games and
Brigade models have extensive ranges of spaceships. They're intended to be large capital ships, but some would work well as fighters.
There's also quite an extensive range of Star Wars extended universe ships on Shapeways - all the things that
FFG hasn't got around to making yet.