It is electrical box dependent and if you have the empty/blank slots to allow for the whole house surge suppressor reside in your current cabinet. I went to my local electrical supply store for assistance. They had my unit in stock so I purchased it and installed it myself. It was relatively easy to install.
If you do not have the empty slots then ask your electrical supply store which contractors are purchasing said units for they will be the most experienced and economical. When I started down this path, I called a local electrician, he didn't know much about them but was willing to charge me way too much money to pick one up and install it...tried to rip me off.
You can check this forum or one of the other ones (IIRC, Audio Asylum and Home Theater Shack) where it was discussed last year and provided a wealth of information especially on the separate units.
Even with this in place, you still would want to us point of source units as added protection for your expensive pieces.
Good luck and remember electricity kills
so be very careful,