These are great suggestions, but there is one more option. If you are good at getting things like glass smooth, and have the $$ and time to spare, check out Chrome Tech USA. They are an outfit that creates show quality chrome for model car parts. They can provide you with free schematics on how to make and mount the parts to a chroming rack, or supply you with a rack at a minimal charge, or for a bit more $$ can mount it for you.
The other option is Micro Mark sells plating kits, but they are meant for surfaces that are conductive which is something our Styrene is not. However there are sprays out there, that are designed to give a conductive surface to plastic parts, just so they can be electroplated. You'll have to search on electroplating plastic parts or something like that to find them, but they are out there. Kinda pricey up front, but in the long run pretty cheap. Especially useful if you like to build kits which have huge seam lines or joints right in the middle of a nice chrome piece.