Sounds like they're map images (going by the KMZ file extension you mentioned). @limfx & @kalju - map images tend to require very high resolution imagery (at least from my experience working with things like ArcGIS imagery data).
So going off of what PP said...they'll need better ISP's if you're wanting to push that much data. Unless you can stream the data with something like Esri's ArcGIS products, if mapping is indeed what you're doing.
Thanks for the suggestion to go with Esri's ArcGIS. I spoke with them this morning and it looks like they have a great solution to my dilemma. Thanks to all that responded...looks like my question has been answered!