Look for a shop in your area that has a Hunter GSP9700 balancer system. This system allows a true dual-plane balance for wheels. When mounting new tires, the machine has a roller that imparts a load (about 900 lbs.) which allows the bead to set around the rim. The operator can even input the type of wheel (let's say the ZR-1 5-spoke for example) and allow the balancing weights to be split over two adjacent spokes. In addition, the system allows the weights to be placed anywhere along the wheel.
On my wheels, I have stick-on weights on the inside of the spokes completely out of view. The inside plane has regular clip-on weights which os OK as they can't be seen.
check out this link and then click on the "Locate a GSP9700" to find a shop in your area.
http://www.hunter.com/pub/product/product.htm
You will probably pay extra for using this machine but it is well worth the money. I had a set of tires mounted and balanced for open track days and at 130+ there is NO vibration!!