Steve Jackson’s GURPS (Generic Universal Role Playing System) is one of the grand old men of the role playing world. The game provides one of the most realistic, detailed gaming systems ever. Because the combat system is so good, I know of many miniature gamers who use it for skirmish games. Steve Jackson games has released a free “lite” version of the rules as a pdf download.
I loved Space: 1889. The setting was fantastic, and I also liked the RPG system. But for those who prefer a more nuts and bolts operation, you could try this GURPS conversion for Space: 1889
For GURPS players, here is an online automated treasure generator.