The TPU requirements are all over the ballpark depending on the season. The TUG sightings board is probably the best place to get a handle on that. The recent sightings I've seen were 40-42 TPU for one bedroom DVCs in Feb-May 2014.
On the bright side, RCI uses generic TPU for all of the Orlando area, so
DVC exchanges tend to be great bargains.
There is also more availability than I would have thought, but you're going to need to do an ongoing search if you're in RCI Weeks. In RCI Points, you will have to search daily because there is no ongoing search capability there.
From what I've seen recently, DVC appears to make bulk deposits at about 5 1/2 - 6 months out. They did a bulk deposit yesterday into early May 2014.
Some of the more experienced RCI folks can give you a much better picture than I.