You can electroplate SLA parts. Copper is electroformed over the part first and then polished and then electroplated in whatever finish you want. The issue I found is that electroforming adds about .010" to the thickness to every surface of the part. So make sure you factor that in to the SLA part if tolerance in important. While I haven’t used them, I have seen samples from B&L Plating in Michigan.
http://www.blplating.com/index.htm
Vapor deposition (metallizing) can look perfect - the finish on the SLA part has to be perfect and the under and over coat has to be perfect to get a perfect mirror finish. We do our own on cosmetic components and it is beautiful. The color of the finish is different than chrome, whiter, since it is aluminum but that can be adjusted by tinting the over coat. Under and over coat adds about .008" to the part surface
Silvering is another option and can also look perfect – same considerations as metallizing. The silver color is very warm and requires a deep tint of purple over coat to make it look chrome. it is very convincing. Under and over coat adds about .008" to the part surface