It does sound like you are interested in renting points from a member, so you should go to the rent/trade board posted above.
You can get a lot more information about renting from that board, but I wanted to address your question briefly.
There is a difference when you rent points instead of making a reservation through Disney. First, you are dealing with an individual and are subject to the agreements you make with them and the risk of dealing with an individual instead of Disney. You may have more restrictions on cancellation and will likely be required to pay in full well before your trip.
Second,
DVC resorts are different. They are deluxe Disney resorts and offer additional room amenities (ie kitchen and laundry in 1BR and bigger), but they do not feature daily housekeeping. Because of the ownership system, availability may be more limted in DVC if you don't plan well ahead. There are other differences, but this gives you a start.
You can learn more about DVC through the FAQ for this board, but I wanted to let you know that there are definitely some differences. Whether you consider them plusses or minuses is up to you and your situation. Of course, if DVC style accomodations suite you and you go to WDW regularly, you may want to consider becoming a member yourself and enjoy it for many years to come. That's what I did.
