i have a 8GHz differential clock to convert to single ended. Is taking one end of the clock enough? what are the risks of doing so?
Unless you have experience with common-mode noise, modelling coax, stripline, microstrip, ground effects and understand the group delay distortion effects of unequal skew paths down to the millimeter and know what an eye pattern looks like and how to optimize, you can easily destroy the integrity of a data signal as you suggested.
NB7VQ14MMNG is a popular chip for selecting external Group Delay equalization for Differential In and Out, but it does show a single-ended output in a simple block diagram. These might be useful for SMA connected test points to a single-channel DSO