the hf das are awesome! i just bought a 3rd one for use as a 3" polisher/backup polisher.
you should pick up the following if you wanna be cheap but super effective
5" lc da backing plate (ag, $18)
2x 5" meguiars mf cutting discs (ag, $20)
6x 5" lc flat polishing pads (ag, 4x white, 2x black...