If you look at the different plans services you may just find the plans for the plane you are looking for in the size you want. It's often as not cheaper just to buy the plans. Who is going to cut the foam cores for you? I'm the worst foam cutter I have ever seen so when I see plans calling for foam cores I avoid them. I have used Kinko's to enlarge plans for me. The wood does also go up in size but that isn't a big problem. Most the time the same size wood used in a 60 size plane will work for the bigger plane. You just have to use your head and think about it during the build and use the size you think is required. For things like canopy's and cowls you can look in magazines for ARFs of the same plane that is clost to the same size and buy there replacement parts. I also use Fiberglass Specialities for parts. Finding an ARF that will work is a lot cheaper though. What you want to do isn't a big deal but I don't have a local foam cutter so it wouldn't be my choice of plane. I did have some good cutters before I moved but that's a thing of the past.
