Any gloss black paint will give you a finish like that, though let me warn you, I did it to my front badge and it looks sh1t. Halfrauds sell plenty of spray paints, primers, wet & dry paper, etc that you would need.
The issue with a gloss finish is the contrast between the vivid black badge and the slightly greyed grill, so you would either have to paint the whole grill

, or it needs to be in good nick.
Someone once said (Stealthwolf?) that a wee spray of WD40 keeps the grill black, but can weaken the plastic...
Not trying to put you off though..........
