have done a few and am about to send a few more off to get done as well.
i fitted the tyres myself after relacing the wheels and had no problems with tyre levers on the powdercoating.
3 rims cost me $100 and they said they'd do 4 rims for the same price. so this time round, my worst looking 4 rims will get the gloss black treatment.
it pays to sand back any gouges or chips before sending them to get done as the easier it is for them the cheaper it'll be for you
silver might look good too