For booking the villa part there are loads of sites out there that give you the facility to search for what you are after.
One that we have used is
http://www.orlandovillas.com/
but I also know that
http://www.vr360floridavillas.co.uk/ is dependable due to comments made on this forum.
before you go trawling through all the ones that are available have an idea in mind as to what you are after e.g.
how many bedrooms (and how many of them need to be masters/doubles)
swimming pool that is not overlooked and south facing
games room
free internet, wi-fi and phone calls to the UK (maybe not important to some but as you have 2 teenagers with you it probably will be)
the location that you want to stay in (Ponciana Blvd/H27)
do you want a gated community or would you be happy on a standard community where there is no gate
The first site I linked has a facility that lets you specify most of the above, then sends an email only to those owners that meet your requirements. If they have availability for the dates you want they will get back to you. It certainly cuts down a lots of searching and endless emails from you making requests yourself.