Titan forge’s patreon had some cleverly named " Gigeroids" in their September release last year. There weren’t a ton of different sculpts, but they were there. I would include a very helpful link to the files for a set of three they have for sale on Myminifactory, but apparently I cannot (What’s up with that?). Search Gigeroid Cyber Forge. It should come up.
If you don’t have a printer, I’m not sure what your options are, but there has to be a way you can get them printed. I don’t use myminifactory other than a repository for files Patreon creators send me, so I am sorry I can’t be of much help in that regard.
I do know that some old 40k Genestealers make good xenos. I bought 6 or 8 poorly painted ones from Ebay just for sci-fi game xeno stand ins. You might try that. Way better than paying full price for new.