I just finished a project such as yours and Dennis was instrumental in helping me through the project. One thing that differs in our projects is that my boat had had seats installed previously and had been removed leaving some of the anchor points damaged but I had the locations. If your boat never had pedestals before then you will be locating the mounting location yourself. On my 205 tournament the seat mount was very close to the stringer system so if you don't position the holes just right, there will be no void to work with for installing the Togglers. The other thing that wasn't addressed in the thread that Dennis referred to was the fact that you may have to deal with foam removal to provide that void for the togglers. I did it by making an "L" shaped tool for my drill out of heavy gauge spring wire and spinning it under the deck through the bolt holes. When installing the Togglers be gentle, they are made to break off after you get them set to your deck thickness so any rough handling and they can break before you are ready.(this is first hand knowledge). I ordered the Togglers from Amazon but found out that West Marine stocks them so if you have a WM store nearby you are set.
One of the guys helping me posted a drawing of the rigging tube layout on my boat that he got from the Grady website. It was great info when it came to working through the deck. I have been unable to download that myself but if you can do that for your boat it would be a good first step.