caravan aerials

hi, can some one give me advice please we have an status non digital aerial this was fine on analogue, but now we are on digital its no good, so i brought a tempory      aerial, now i want to change the old aerial on the roof to a new one that picks up digital, i have been to the caravan shops and they all advise the new status directional 550 aerial at £150.00 but this needs new holes cut in the roof and new fixings, but i have also seen a new status 330 omni-directional aerial which fits in the place of the old one with no cutting or new fixings. i have noticed that both aerials are not advertised as digital and it seems its all about the vision plus digital amplifiers, if this is the case will my old status aerial work if i fit the digital amplifier, any help would be great on this subject as shops seem to want me to spend, thanks nige