I am really big guy, and for our tandem I built 48 spoke 622 wheels, 4 cross, with Wheelsmith DB14 spokes, Wheelmaster MT1110 hubs (cartridge bearing, steel cassette body) and Velocity NoBS rims. They work very well with absolutely no issues on a bike with a GVW in excess of 600lbs. The spokes have relatively high tension, and are properly stress relieved.
The wheels that I have built with Sun rims always take longer to build, because they are not as flat and round as the Velocity rims I have built with. This also results in less even tension for a given state of true. All of the Velocity rims I have built up have ±0.004" or better runout both radially (hop) and axially (side to side) with even tension all the way around. I cannot get a Sun rim to that level of runout with even tension.
As @
Bill Kapaun mentions, the spokes with 13 guage elbows are potentially stronger; if you go that route look for a premium spoke with 13ga (2.3mm) elbow, 15ga (1.7 or 1.8mm) middle and 14ga (2.0mm) threaded end. DT Swiss DT Alpine III is one, Sapim Force is another, there are others.
The 1.7 or 1.8mm center section gives the spokes more compliance so that they share the load better than thicker center section spokes. This results in a stronger wheel under real life conditions. Whether you need the strength or not is another matter.