Name of sci-fi novel?

[Paul&Renee]

Space station on Oort cloud (I think) found by humans, people have chance to take FTL ships from that space station to unknown location(s). Most are never seen again but some come back with technologies that make them rich. Story is about one individual that makes it back and ends up very wealthy. He has a virtual computer friend he calls Einstein. In later books humans finally meet the alien race.