Yes the brakes will fit. Correct me if i'm wrong, but i think the only difference is the Cobra t-45 is a little more beefed up. Maybe it has stronger forks and synchros...?
Yes they'll fit, but *barely*. There is less than a 1/4" (not even enough room for a finger) gap from the caliper to the back of the spokes. On the other hand, with cobra wheels on a GT, the gap from caliper to spokes is enough for a whole hand.
Don't assume they will fit because they are 17". If the offset is not right the calipers will rub on the spokes of the wheel. I would do one front wheel and check your clearances before you go any farther. Better to be safe than sorry.