i’ve been running a campaign on roll20 for about 15 sessions now and to be honest, there isn’t a ton of resources out there.
for tokens, i use regular order markers and mines from the war game as my momentum and heat markers. Shadowplans on DriveThruRPG allowed me to build a pretty neat map. they just dropped a new set which i’ll also probably pick up soon. otherwise, maps from the core books are good, but i’ve found that i just need to set aside time to manually draw systems of the Human Sphere. i made my own versions of the Human Edge and Paradiso and while it took a long time to draw a total of five asteroid belts, it’s one of the things that my players remark on positively, so a worthy investment of time.
as far as other art assets, i steal liberally from Corvus Belli’s infinity site. also, a lot of the artists commissioned for the Modiphius books also have their work up on Art Station and the like, so you can find that out there as well (Vincent Laik’s work is really good). i write summaries after each session and try to use either a piece of Infinity Dossier art or the like to put a relevant visual on the last session. and when that fails, i try my hand at drawing… it’s coming along, and some of the resources like the hacking holos that CB has on their site add good flavor. the IncompTech songs are good an really help boost the immersion on roll20. “Aggressor” by Kevin McLeod is my standard battle music. just make sure you don’t blow out people’s eardrums.
i just recently implemented some quality of life upgrades in my game which you might find helpful. first, implement the character sheet and build the combat dice table as it instructs. rolling combat dice was a struggle for my players, so having a built in roller is really good. you can build a macro to have players roll their damage and it’s super simple. mine is literally /roll ?{Number of Dice}t[Combat-Dice]
there’s also a good 2D20 roller you can implement via macro–not mine and a bit beyond my understanding, but Silvrye’s work has been good so far. if you are a paid subscriber to roll20 with access to the API, you can implement this concept from Bast L to leverage the Infinity character sheets to track momentum and heat pools as well. not too hard to link those attributes up to tokens and from there you can have a single icon for both (or separate for each) pools to provide a counter. it’s a really cool implementation, but fairly expensive if you’re just dipping your toe in. you can increase these attributes manually without the API, but tbh, i started by just managing counters, adding and deleting them as they were earned and spent.
lastly, and i hate to say it, but there is not a lot of Infinity RPG support. so, when looking through the roll20 forums (which are very good), trying looking at what folks have done for Star Trek and Conan. since hte underlying mechanics are similar, you can usually just tweak the work for those 2D20 systems to find something usable for Infinity.
happy to answer any specific questions you might have. i’m pretty new to GMing Infinity myself, but happy to share whatever lessons i learned to make it easier for you and your group.