Depends.
If you're looking for new models as in Heresy stuff like Sicarans, Spartans and so on, there are a couple of alternatives. For 2nd edition vibes, there is a
d10-based system called Imperius Dominatus (
https://imperiusdominatus.org/) made by the people who developed NetEpic through the decades after
GW let it go.
ID incorporates basically everything
FW has written about in their black books. If you like Epic: Armageddon's tighter rules instead, then you should look for the Australian EpicAU lists that do the same in E:A framework. Their wiki has been down for some time, but can still be reached through Internet Archives (
https://web.archive.org/web/20200605220948/http://epicau.com/mw/index.php/Legion_Astartes). EpicAU development is slow and mostly happens over at their Facebook group "Epic 30k".
If you're looking for newer
40k stuff like Primaris, there are some drafts at TacCom's kitchen sink lists, but those units don't really differ much from the previous entries at this scale. 30k aside, fan groups that develop lists for various Epics have pretty much frozen the aesthetics at the 2000's range of
40k without attempting to shoehorn in every new model
GW makes.