You will need a copy of the owners ID and their housebook, and a copy of the properties housebook. And maybe more. Read the manual for the site, it'll tell you.
You will need the same documents, usually along with some kind of letter or lease confirming you're staying at the propery, if you go to Immigration to do it there.
There's no retirement-type visa you really qualify for, but maybe look into the DTV VIsa if you find a activity you would like to do for at least 6 months?
Or even the ED visa and make an effort learning the language. Only applicable if your disability allows you this much acitivity, of course.
The transfer method of proof of income just needs to show the incoming international transfer. You can do whatever you want with it after you receive it.