Gentlemen, thank you both for your further explanations, and generally your patience with me. It is clear to me that I have not read enough parts of Schewe's The Digital Print, even though my copy sitting right here.
At this point my takeaways and further explanations are:
(1) I might as well spend the $47 + s/h to rent the device and see what I get, because nobody has suggested a specific alternative, at least that is readily rentable in that price range.
(2) Argyll + CMS are by all accounts more capable than the lower-end X-Rite software. My concern is that if getting up to speed with their use is a slow process, many reports indicate that they will cause problems with my using the X-Rite software. Currently I use it to (periodically) run my ColorMunki Display, and I could use it to build printing profiles. Maybe I need to dive in--but I do worry that a week's rental, during which time I'll have my regular work and family duties, won't suffice.
(3) I'm sure the lighting at my work can be a problem, but there is no good solution because for the large majority of the time I'm there, window light is a major contributor to viewing light on any photo there, and of course it changes a lot with cloud cover, season, time of day, etc.
Anyway, thanks!