Choosing a DAC for Amateur Radio applications
Ok, so after learning more about radios in general, I learned that you don't necessarily need to sample at 14MHz to digitally read a 14MHz signal.  You can use a local oscillator and an RF mixer to down-convert the 14MHz down to something easier, like 1MHz.  This is what you sample with the DAC.  So the required DAC really depends on what intermediate frequency you choose.