The standard way to provide datasheets online is as a PDF document. So, in general, entering the part number and pdf (e.g., "SAD1024 pdf") into a search engine will get you links for the datasheet of your choosing.
The MN3007 can substitute for an SAD1024 functionally in many, but not all, instances. The SAD1024 contains two series of 512 stages. In some applications, they are used in series, in which case an MN3007 can sub, IN other applications, the SAD1024 is run as a pair of 512-stage devices in parallel, for noise minimization purposes. In those instances, you would be better off with a different device, which is unfortunately every bit as unavailable as an SAD1024 itself.
Note that the MN3007 is an 8-pin device that can not be plunked into the socket for an SAD1024. You would need some sort of retrofit board. the Ross flanger is, like many of their products, basically the same as the MXR unit with a couple of minor changes, right? Check over at the diystompbox forum and see if someone has come up with a retrofit board. With over 20,000 members, somebody has to have trodden down that path before.