Space truckers is your best option if you're not keen on colonial marines. You can just make them freelancers so they'll do any job. I'd suggest reading Alien universe books for some ideas, but like you said, you don't want xenomorphs in every session. I'd suggest reading Aliens Bughunt which has ei...
Just wanted to say thanks for sharing your creations. I'm gathering them together and adding them to a module of fan content for the ALIEN rpg on Fantasy Grounds.