I've looked into renting for family members before, and I honestly think it's a huge hassle, and I'd personally never do it. But lots of people do, so take that as you will. In my limited research I've found that the kind of rental you need are snapped up asap. 390 is a lot of points to find avaliable for rent. Also, it doesn't seem like there are a lot of available rentals until just a few months out from the travel dates.

We haven't stayed at Jambo House, but we have stayed at Kidani Village in a 1 BR. You are correct about the locations. Jambo has an advantage if you like to eat counter service meals at the resort. For us, Kidani has a huge edge for having an extra bathroom (so you'd have three in a 2 BR). Another plus for Kidani is that it's the first pickup spot for the buses.

We have friends staying in a 2 BR standard view at Kidani in a few weeks, but I can predict the view will probably be parking lot or vegetation. There are overlooks to check out the savanna, so if you plan on doing parks for most of the day you can easily sacrifice a savanna view to save money.

Sorry I can't offer more insight on the rental process, but I'm sure someone else can.