From the Lik Sang website faw concerning the Bio Gun:
What screen resolution will the gun work with? (2002-04-16)
The gun should work at any resolution as it includes a VGA card adapter that interfaces with the gun and the PC. (2002-04-19)
Does this gun support/work for MAME games? What does the PC detect it as? (2002-07-31)
Mame32 v.61 and later support PC light guns. To enable light gun support, go to Options -> Default Options -> Controllers -> check the "enable lightgun input" box. (2002-12-04)
Will this gun work on a Television (TV OUT) or only a CRT Monitor. I know the ACT Labs gun will only work on a CRT Monitor. (2002-12-18)
This gun will not work on the tv out of your pc. it will only work on your monitor, since your pc cannot register any shots fired at the tv. (2002-12-18)
Does this gun fuction as a mouse or a joystick? (2003-02-06)
This gun functions as a mouse. (2003-04-19)
Can you use 2 light guns on the same pc and use them to play MAME? (2003-04-12)
Actually you can but the thing is the program you intend to use it for must support light gun support for multiple players... (2003-04-22)
I don't know who answered these questions or how accurate the answers are, but I guess we would just have to see.
Thinking about it now, I suppose it might be remotely possible for a PS2 gun to work in dual mode if the buttons were programmable and assignable to different gun so that each gun had totally distinct buttons (Like if gun1 had mouse buttons 1,2, and 3 and gun1 had mouse buttons 4,5,and 6).