AD8343 for 6 MHz frequency mixing

Hi,

I have an application that requires taking the difference of two differential 6 MHz frequencies. I am considering using the AD8343. The application is for a test instrument. I would hope for output resolution of the difference in the Hz range. Is this the right IC for the job? As the examples in the product pdf are concerned with 70 MHz and above, can you comment on how design considerations - e.g. biasing resistor network - may change for the much lower frequency of 6 MHz? Also, must the LO inputs be square wave or is sine acceptab

Thanks