milofilo, You'll receive many good suggestions from economy to expensive. The most often suggested parameter is to have a minimum of 36 spokes. Some are comfortable with fewer spokes and some opt for more, but 36 spokes work well for a load that can't ride light. Do you know what the rear hub spacing is? I'm guessing 135 mm because of the rear hub.

I built my primary touring bike with a budget wheel set using Sun CR18 rims, straight 14 gauge spokes, and Alivio hubs, and following an initial tune-up session, no problems.

Brad

PS I've used 32, 35, and 37 mm tires, the 32s are fine.