Adapters are a bit of trial-and-error unfortunately. I tried a few to see if I could salvage my old Logitech Wingman Interceptor, but in the end I gave up.
Anything more than a 2-axis, 4-button joystick is going above and beyond what the game port is specified for. With a real game port you can get around that using drivers and stuff, but once you put a USB adapter with its own drivers in the middle things start to get tough.
Your best bet would probably be a PCI game port adapter if you can get one, but I think they're pretty much extinct. Apparently Microsoft stopped shipping game port drivers in Vista too.
Safe computing is a habit, not a toolkit.