I have found the DriveThru search options to be frustrating too. It's not helped because they have several separate sites, and some publishers will only add their products to one or two (commonly DriveThru and Wargame Vault). Searching also presupposes all publishers will use the same keyword terms in their products, and not all do.

Of course, it's possible the kinds and styles of symbols you're looking for may not exist anyway. We have kept coming back to requests for modern and cyberpunk symbols before on the Forum here, for instance.

Try typing general keywords into the DriveThru search-bar - such as "mapping icons" or "map symbols". If you try to make the terms too specific, the search facility tends to get quite restrictive, so unless you know the name of a specific product you're trying to find, it's probably best to avoid them.

This is a pretty complex set of tasks you're hoping to accomplish here, but as long as you're happy to put in the work yourself, it should be perfectly possible. That may depend on how comfortable you are working with the mathematics of orbital mechanics, however, and exactly what degree of precision you're hoping to achieve.

I'm not aware of any tools that will allow you to do all of this in one, but you may find some of the tools linked from the Worldbuilding Links and Software page of the Orion's Arm Universe Project website helpful. Note that some of these are only available via the Wayback Machine archival website now, and may use older software types to function. I've not really done much with this in a long time, so can only hope some of it may assist!

Unfortunately, the few folks I know, or knew, who did this kind of thing tended to write their own programs to do it, and while that may be an option for you too, that's not something I've had any experience with, sadly.

Good luck anyway!

Not sure how practical this may be, as it's not a style I've played with as yet, but it might be worth adding some hedgelines to the outer edges of the fields as well. Just looks a bit odd with so many fields where the wildlife can just wander in and graze at will.

Looks as if you've accidentally created a maze-mapping toolset along the way to me. Change the city-blocks fill to greenery, and off you go!