I think you can choose whatever methods you like best. Scotchbrite pad or fine sandpaper, any paint system will do but ideally use a primer that is designed for plastic so that it gets a good grip, such as an etch primer, I often use Halfords Plastic Primer. For the repaint of my Eurosport I used fi...

I have a carf eurosport with single pipe, I fitted two of xicoy's 30 led rings outboard of the jet pipe, they work extremely well and don't look like they are far apart as they are, when they light up. see link in George Evan's post above. Two rings, controller and shipping was €93