I have installed pumps from Aquaflo in place of the official Watkins units (Only in non-warranty repairs) and I have saved hundreds of dollars, and they have worked just fine. Watkins uses a mix of pumps, but if you end up with one of the Chinese models, well, just don't.
If you want to order, use your pump type (Aqua Flo XP2) and the number of speeds (I think one of yours is a two speed and the other is a single speed, but check) and then voltage and amperage. You only need to be close on the amps.
Also, you might consider taking your pumps to a motor shop: I used to take them apart and put in new bearings in the case of a noisy motor. Easy peasy - I would usually just get a 'wet end' so I had all new plastic pump components.
Final thought: you may or may not get the exact same motor, so the cooling air duct may not fit onto the new pump. Not really a problem (I'm sorry, did you say you live in Death Valley?
) Just put the duct near the end of the motor and you'll be fine. Many tub makers don't run cooling ducts and it's fine. If it matters to you, either ask your supplier for the same motors, or just go ahead and pay close to double for pumps from Watkins. But as mentioned above, do NOT install them if they show up 'made in china.'
HTH