Ok my 2 peneth. Depending on the seriousness of your swirls you have 2 choices. If they are really bad you are as well paying £2-300 to have your car buffed professionally, it works out cheaper than buying the gear your self. Then all you have to do is make sure you don't put the swirls back in by using a good wash and drying technique. Trying to remove these marks by hand is near I impossible.
It is not all bad news though as there are products out there like Dodo Lime prime that will give a bit of cut and fill a lot of your swirls. You can also use polishes with fillers on to mask the swirls, so for about £20 you can probably mask the problem. Don't fall into the must have a DA unless you are mad into detailing, as a good DA used properly will only be needed once in a blue moon and by the time you have spent practicing and trying different products it is cheaper to pay a professional.
Just my opinion
For the others my choice is Meg's G220 and the Microfibre system.