Kim: Check out Tiff Needle's drive in a SF GT40 at the Kyalami circuit. Looks as though there was no need for canards as he was hanging the back out much of the time. I don't know what the weight difference between your car and the one being tested. Looks as though this one is powered by a Roush Windsor with ci block and aluminum heads. Couldn't see what tires were on the car.
YouTube - GT40 driven by Tiff Needle
As for handling, go easy at first, then gradually build up your speeds as you get accustomed to the car. Make adjustments as neccessary. Dennis can surely help you with this.
As for how replicas handle, I ran my ERA with a 331 against a Porsche Carrera and a supercharged Z06 on VIR's 1.64-mile south course. With considerable elevation change, it's a real test of braking and off-camber, down-hill handling with some high-speed stuff thrown in. Note: As per Dennis' recommendation I installed the /CR76ZZ AVON 15-inch 215's and 295's on the car. I started in a single line behind each car in separate sessions. Result was the ERA was better than the Carrera in the curves, twistys and long straight. It was neutral in all situations. As for the Z06, he could pull me a little down the long back straight, but not so much that I couldn't gather him in under braking and in the turns. Went by when he cross it up in an uphill left hander. From then it was audios.
Be prepared for the huge smile on your face.