Pampos,
Personally, I would definitely follow 1000 grit with finer grades (at a minimum 2000 grit). Like mentioned, try a small test spot to see if something like 1500 will work for you, or if you need to step down to 1200 or 1000. Once you find your starting grade, try 2000 grit to see if it will effectively remove the lower grades sanding marks, and then your polish to remove the 2000 grit marks.
When I'm wetsanding, the polishing steps are the most time consuming. So if you can get the sanding marks as fine as possible (I finish my sanding with 2000 grit, and would go to 3000 grit if I could source it locally), you'll spend less time polishing out sanding marks. (Note to self, get 3000 grit next time I do an online order).
A test spot is important. Without knowing how soft and thick your paint is, it is nearly impossible for someone to tell you an exact order of what grits to use. In your instance, I'd test a small spot with 1500, step up to 2000, then a quick polishing (several successively gentle steps) of the spot to check the end results. If they're acceptable to you, use that as your plan. If the OP isn't removed to your liking (and you have plenty of paint/clear), do another test spot with 1200 or 1000, then 2000 and polishing. You can even experiment finishing sanding with 3000 grit to see if it cuts down your polishing time significantly.
Experiment. And enjoy the process that gives you the results you desire.
Dave