TestDisk should be your candidate:
- collect data / capture disk images: Yes (I don't know of a size limit)
- open dd-style files: Yes (that's what I used if for often; it analyzes the structure and, when in doubt, asks you for partition types etc.)
- process the collected data: Sure (wouldn't make sense otherwise). You can even extract selected information, browse through directories, and more. And yes, this includes recovery of deleted files.
It's a while ago I've used it last, so I'm not sure about how far its search facilities went. But it's one of the most widely used tools in this area.
TestDisk is available cross-platform – which includes (explicitly) Windows-7 64bit. A lot of documentation can be found on the linked official page, so you can head there for more details before installing it.