If I were you, I would run around the house and take a few quick measurements to see what max size plier opening you will need for the things you do most. Then buy the smallest plier wrench that opens to the max size you need, so you can then fit into the tightest areas possible with it. I have a feeling that if you do this you will probably end up getting the 10" size if you are thinking about the same household tasks that I think about.
I now have 2 of each in the 7", 10", and 12" size, but I started out with a single 10" pliers wrench and it worked well for almost everything I encountered. I used it for about a year before I decided to invest in the other plier wrenches. Now I have more flexibility and stronger wrenches for bigger jobs, and smaller pliers for tighter areas, but the single 10" can do a lot by itself.
One thing I would recommend is to get the comfort handled version only if you will be doing repetitive tasks over and over. Get the regular dipped handle version if you will be doing lots of individual quicker small projects with it. The comfort handles are nice, but they are also rather bulky and thick, and there is no real benefit to justify the extra cost if you are not using the pliers for very long each time they are used. I only have the comfort handles for one of my 2 pairs of 10" pliers wrenches. All the rest are dipped handles. For me, that overall setup is the most versatile and cost effective.
