I've been advised before that it's best to get at least two of the alloys done as it's virtually impossible to get an exact match with the dark colour Rays. A slight mismatch between the alloys from one side to the other will not be noticeable wheras a mismatch between the two wheels on one side will be - hence its best to have two done on the same side. A company called Lepsons gets good reviews.
As for the paint, I've done a lot of my own research pending getting my bumper scratch repaired. A good painter should be able to do a repair that isn't detectable to the naked eye by blending the repaired area with the surrounding area etc. Pearls are supposedly harder to match, which is why you need to use a body shop with a very good rep. Like you I won't be happy unless the repair is invisible (although bear in mind that there is always a mismatch between bumper and body anyway due to the way paint sits on plastic and metal).
Yet to see a perfect 370 OEM wheel refurb colour match so as - Sipar says ^^^ but in my case I decided to all 4 done and asked that they match the satin alloy on the handles etc - pleased with what they did (powder coated btw).
And noting Sipar mentioned TGM in his previous post as regards the pearl white match, when I enquired about having the stone chips on the front bumper and bonnet done, Billy at TGM said as happy as would be to take my money he strongly advised to have the front blended and onto the front wings as the pearl sparkle does vary from car to car and on each car and helps to avoid any obvious change at panel lines and in my case said the chips were relatively minor and I should save my money!
You might like to pm Will370z who has had work done at TGM..... Not saying that is where you should go just passing on info obtained from one of the rare places I would entrusted my 370 to be painted.