If you can live with a maximum of 60 MHz, take a look at the FY-6600 thread. At low voltage levels, the spectral purity is quite good. The output op amp starts to distort above about 0.5 Vpp. People have done some pretty amazing hacks on them. Some of them are available in the FY-6800.
However, customer support is non-existent. so if it quits working, as happened to me, you are pretty much on your own.