It's worth contacting the hotel directly (ideally a sales manager) to explain you're looking to book a long stay, you're considering a few different properties and ask whether they can improve on price and/or benefits. You may be able to negotiate things like discounted nightly rates, weekly laundry service, etc.

Also look at other booking sites to see if you can do a Best Rate Guarantee claim. Most OTAs only allow you to search for < 30 nights at a time so you would need to break it up into blocks. This could get an extra 20% off the lower rate you find (if you can find one).

Aside from the booking process, if you're choosing between Hyatt House and Hyatt Place and they're equivalent locations, I would usually always go for the HH property and have some form of kitchen. You usually need to book higher category rooms to get a full kitchen in the room/suite.

Depending on where you are in China, you can get some really great rates at higher end properties too. I usually get bored of staying at the same place for more than a few weeks, so I would also consider maybe moving to another property for a week or two every month. It would help break up the stay for best rate guarantee and elite qualification purposes, potentially ticks off another brand explorer brand, gives you a change of scene, etc.