I have a smidge of experience with the chrome paint options. To get the results as pristine as the TSB spray takes a lot of work (they make it sound like it doesn't... not the case). I've not found a good solution in the form of paint.
I'd love to get my hands on the new chrome powder from Eastwood. It's essentially a powder-coat product and might not work for your plastic grill, but check this out: Eastwood Extreme Chrome Bonded Powder
I'd love to get my hands on the new chrome powder from Eastwood. It's essentially a powder-coat product and might not work for your plastic grill, but check this out: Eastwood Extreme Chrome Bonded Powder