Chris, the overhang is pretty much up to you, as a rule of thumb, the more overhang, the less secure the coping will be ( not that the difference between 3/4" and 1.25" will mean that your coping's going to fall in the pool). The real issue is how wide the pavers are, I would not feel comfortable having less than ~80% of the coping secured to the beam (& would be more comfortable with a higher %). I would suggest going with ~ 1", pick something that will allow you to use an easily available 'guide', having them ~'perfectly' straight is the 'cap stone' ( ) of the look of your pool. Good luck with the finishing touches!