Well the der. hanger will not be a problem, every giant dealer should have them; they are the same as on other giants from that era.
I am curious to what you think of the handling. I must say I was spoiled by riding Intense and Nicolai full suspension bikes with very good and stiff rear forks.
I like it (the form) to much to sell, but I don't like the ride. So now it is an extra bike I loan to friends. That's also why it is build up with modern parts.
It is a nice comfortable ride that gives a lot of confidence with the low standover height, good brakes and more than enough travel.
What length (eye to eye) is your (original?) rear shock? I think the geo on mine is a bit weird; if I put in a 100mm fork, the handling is already very nervous, so
a longer fork would be better, but with the 100mm the cranks are already so high up. I was thinking about trying a shorter rear shock to make the head tube
angle slacker and lowering the bracket height.
A friend of mine used to race downhill with one of these with a Boxxer up front (gave it a good head angle) and it even survived his 90kg abuse.