[Rice field rats, Bandicota bengalensis (lesser bandicoot rat) Bandicota indica (greater bandicoot rat)]
The greater and lesser bandicoot rat, not the common rat, are the rats eaten in Southeast Asia and southern China. Not related to the real bandicoot, they are major pests in rice and wheat fields throughout Southeast Asia and India. While they are hunted, trapped and eaten in great quantity conservation status is LC (Least Concern) because they breed at a stunning rate.
These rats are much larger and plumper than the common rat and the tail is proportionately shorter. For B. indica head/body length is about 10 inches and overall length is 16 inches. Photo from blog Tropical Ramblings - I didn't find an email for permission.
More on Rodents & Rabbits.
While California and Texas grow large quantities of rice, we have no bandicoot rats and the USDA is unlikely to approve introducing them. I would not be surprised if frozen ones are available somewhere in the vast LA/Orange County metropolis, but I haven't encountered them. It is unknown if common rat is a suitable substitute but it's way too small to be worth trying anyway.
To prepare a rat (presuming it is already dead)
The main risk involved with eating bandicoot rats is from programs to poison them. Make sure your rats come from an area where no poisoning is being done. This is not a problem in North America because there are no bandicoot rats here.