Hi, the way you receive the signals really does depend on what area you are in. Some use MMDS and some use the standard DVB format.
If your area uses the MMDS "Microwave" system (i.e.. you have an aerial on your roof to receive channels), then you are most likely to need a DVB-T box. Im pretty sure that there is a Dreambox 500T around, but havent seen one recently.
If you area uses the standard DVB system (i.e.. like we have on UK Mainland), then you are most likely to need a DVB-C box. The dreambox 500c will be fine.
Pop into the dbox2 section and do a search on MMDS, there was a detailed thread in there not too long ago bout MMDS and how to set up a dreambox to work with it.
Liam