We are also looking for a trip over a year away. I have looked at literally hundreds and hundreds of villas and have norrowed it down to 6. The one I am most interested in is called Disney-licious and is Windsor Hills, the woman who owns it is from the Kootenys here in BC which for some reason comforts me
I think the only way to know for sure is to have someone who has rented from someone before tell you it is ok, other than that it is a leap of faith.
The chanes of picking one then finding someone on the DIS that has stayed there is slight based on the # of rental villas there are, but if you can get recommendations and pick from there it may be safer.
There are a lot of recommendations on the Orlando hotels board on the DIS
Good luck!!!