By remains, how much do you mean is still intact of the 750? Might be easier to put the 750 together than fit the 750 engine into the 1000. The VFR would make a better commuter than a VF1000R (I'm assuming that is what you mean).
Definitely check the forums CBRVFR noted, there are several former VF1000R owners there. Also check the information on the VFR homepage
http://www.cs.wisc.edu/~john/vfr/ , there might be some good links or specification information.
I think the 1000 engine is larger than the 750 by a pretty good amount.
If you get it running, be sure to check out the COTU (Center of the Universe) ride out of Marietta, Ohio the weekend of May 13th. There will be some VFR's to kick tires with.