Do not reuse the stock hubs as they are very low quality. If you make the change to 700c this is what I would do as I have put this combo on many high mileage comfort bikes.
Velocity Deep V rim, Shimano 105 hub, DT 2.0 spokes. 36 hole, 3 cross front and rear, both sides.
The Velocity rim is the best out there right now for rigidity, 105 hub has the closest spoke hole diameter tolerance at a reasonable price, and DT has the best alloy for spokes plus the treading is not ultra smooth so they bind better.
What causes spokes to break is work hardening (metal fatigue) and when the rim flexes so to the spokes. When things flex the spokes take the brunt of it and "bend" over and over again. If the hole openings in the hub are too loose, then the spoke has more movement there as well. All this leads to the breakage. Sufficient spoke tension is necessary of course, but with standard 27" replacement wheels you will not get the quality a 200lb person needs to have a durable wheel. Just the way it is.
Velocity also sells custom wheels using their house brand hub that are very good quality. I do believe they come with some kind of warranty as well.