Beautiful car, sell the performer intake and spend the extra money on a real gt40 tubular intake. That car is worthy of it (and will add value). The gt40 is only worth the extra money on a car that is really nice and I think yours qualifies.
For the record, I've had a performer, performer rpm (probably the best all around edelbrock intake, but they didn't make many of them), rpmII and a gt40 tubular.
On another note, shouldn't your car have a front bumper filler?