I generally find the 0/O difference to be vastly overhyped - maybe of a "what-if" that comes from the natural OCD-ness of programmers, though that's pure speculation. The number of non-contrived cases where there is actual reading confusion between the two is exceedingly minimal, especially once you factor in semi-modern editors. One of the fonts I cycle through is TheSansMono Condensed, which by default has a non-slashed zero. I've never really found it to be a problem.