Not cheap but would suggest:
1: if your not used to machine polishing
Dual action polishers
2: Better results can be had (quicker) but easier to damage if careless
Rotary polisher
I've got the DAS 6 dual action, got the Sonus kit with it and its very very good, also now got the Menzerna cut/ polish and works exceptionaly well...
To buy the rotary on its own is good value but you need to add the price of pads etc etc so it soon goes up