i wouldnt use filler if i was doing it. i did a renault 5gt turbo full resto with a mate of mine(i did most of the prep he painted it) and the bodykit had like dipple effect all over it(was soppost to be like that) so i hit it with a DA sander then wet n dry untill it was smooth as a babies ass, then got painted with the body
i also did a astra g centre consol that was textured and rubbed that down smooth, its time consuming but cheap to do yourself, you could save shit loads, as all they would need to do is paint it. i cant see that costing more than £100/£125 (well round here anyway)