Home offices are one of the things you'll get the least investment money back from right now. Offices are portable. People work from their phones or tablets. No huge built-in needed for that. You can see that in your own plans which list the room as a living room instead of a study or office. Offices don't sell.

What kind of office equipment is necessary for you as a minimum? Do you need a printer, copier, fax, desktop station, artist's station, writing area, etc? What types of things are you storing? Files, gadgets, books, supplies? That will dictate a lot of what you need.

I think your best bet would be an L-shaped configuration along your long, blank walls. I'd go with a corner shaped desk...in the corner. It should provide ample work space. As you need book cases, shelving and file cabinets place on either side of your desk...keeping in mind what you use most often and keep that closest to your desk. I'm suggesting all of your book cases, shelving etc. be concealed behind doors. It makes for a more relaxing, neat, work environment. Spoil yourself and include a comfy lounge/chair and end table, perhaps on an angle in left hand corner by the bay window. I'd advise against an executive style desk, as I find these look best when pulled into the room...but becomes an issue when trying to install your computer for hookups, and electrical outlets. I angled your desk away from the window as I personally find it a distraction. I'm sure you'll get more great input from other posters. Good luck!

Whoa. I think we live in the same house ! Only our slot car track is upstairs. Look at my pic. What did u end up doing?

Did you look through the office photos on Houzz?