You can purchase aftermarket wheel rims from a local car accessory store or online. If you shop at a local car accessory store you can actually touch and feel the rims before you buy and if you have any questions a sales person can answer your questions. If you shop online you will have less help, but the benefit is in the savings, you can save hundreds of dollars compared to the local stores. Many online automotive merchants offer you wheels balanced and shipping for free.
If you don't want to spend all of your money on one chrome wheel but you still want that chrome custom look, an alternative to the $5,000 spinner chrome wheel is Spinweel Spinners, which will run you about $300. Spinweel Spinners are add-ons to your custom chrome rims, they are designed to adapt to the wheels on your vehicle.