Sill Painting

Have been meaning to get around to it for ages, but the leading edge of the sill ie the bit that wraps around and into the front wheel well has been worn back to bare metal and dreaded rust. Have also noticed that wing is rusting and bubbling a little on the lip in the wheel well but thats another issue.

Couple of things:

1. I have cleaned sanded and sprayed stone chip black hammerite but was confused as thought stone chip left that bubble effect that the entire sill is in but its flat.

2. Would you spray the pearlesent paint over the top of the flat black and then laquer or does it not matter as its black anyway. Basically what im getting at is when you do your sills do you put the colour code paint over the top of the stone chip or not?

Any other help would be appreciative as i think i may of made a mess!

oh and as a backup what do you recon the rough price for someone to spray the sills are professionally?