Thanks for the responses. . .
unfortunately, I have downloaded the plugin and played around with it but I don't think it is quite what I need. Again, it is entirely possible I am doing it wrong but who knows.
What I'm wanting to do is create a list of books in the GUI (calibre) and then sync that specific list to my Kindle. This would allow me to change out what books I want on the device at any given time without taking up so much space. Plus it would help me to create a reading list. It is a little overwhelming to search through all these thousands of books to find the NEXT book to read. I know, first world problems, right? lol. Anyway, if there is a way to do this and you wouldn't mind giving me steps for how, I'd really appreciate. Thanks again!