So if you are continuously breaking spokes that is a sign that wheel is failing and has issues that will be chased until you decide to give up. If you are regularly breaking spokes that could be a sign of a poorly built wheel or a wheel that just can't handle your weight or power or both and you might want to have someone competent build something stronger or relace this one as a 2x wheel at least if it has enough spokes. Radial lacing on a rear wheel even on the NDS is not ideal. It can be done for a really lightweight rider who is gentle on equipment but it doesn't sound like that is working well for you.

You can certainly just measure your spokes and order more and go around the wheel replacing spokes all the time but I wouldn't let a customer do that it is just silly unless it were some super rare rim and hub that you cannot find anywhere and you are dead set on keeping it for some reason I would just have it rebuilt with at least 2x using brass Secure Lock or Pro Lock nipples (or whatever locking nipples your favorite spoke maker has or drop some spoke freeze in while building) and double or triple butted spokes. I would go to Sugar Wheelworks or Peter White or Bill Mould or some well respected wheel builder who really knows their stuff and have them build it and maybe also make suggestions giving them all the info you have given here.