I am pretty sure they use HASP hardware keys (I know Live! uses them). If so, you could proably just put two of them in different USB ports.
Most likely though, it is two different boards. The kits aren't that expensive. Complete is just a software upgrade for around $500 and you can get the red boards on ebay for 200-600$ depending which year (the software upgrade works on all Fore platform boards), Silver Strike kits are about $1900 I think as well. (Pardon if my numbers are a bit off, but I am pretty sure those are ball park)
A kit ready GT cabinet from TLC (factory that makes the coin-op version) should only run you about $1200-$1400 for a 27" but you could probably make your own for less.
Those of you who haven't played Strike, it is a hell of a game. I would love to have one in my game room.
Cheers,
Arcaman