Hello,
I'm very happy that I have found your job posting "Map for SquareSpace Site" because it looks like a job specially made for me. And I'll tell you why. I'm a Cartographer and a GIS Expert for more then 10 years. I have studied cartography, geographic information system, remote sensing, WebGIS etc. in France and Brazil. I work constantly with the main maps' softwares on the market: ArcGIS, Global Mapper, Quantum GIS, TNTmips, AutoCAD, Philcarto etc. Until now I created maps for a lot of different clients: public institutions, websites, university professors, students etc.
I have analyzed your post and I understand very well what the work involves. Regarding the spatial data, the best software for your map is ArcGIS. I have the 10.6 payed version (one of the latest versions), so the work will be fun and quickly done. I can start the map as soon as possible and in one and a half, max. two day it will be done.
If you want to know more about me and see samples of my work, have a look on my profile. If you have any questions, feel free to ask via chat! I'm also available on email and Skype.
Best regards,
Florin-Alexandru E.