Gary,
Sounds like you have an excellent starter station there. :) You can certainly use the FT-847 satellite memories, but my strong suggestion is don't. They work pretty well with HEO birds near apogee where the Doppler shift is small and/or constant, but for the existing LEO birds, that isn't the case. My recommendation is to use one of the computer control programs to drive the frequency of the rig. You will enjoy the convenience, and on the SSB linear transponder birds, so will the people you work.
SATPC32 is truly excellent, and the reasonable registration fee goes completely to AMSAT for development. Ham Radio Deluxe also does a good job, is free, but the Doppler correction is a bit wonky. Simon is going to fix that Real Soon Now. Note that if you do use SATC32, you will need to transfer the QSO info manually, but I find that a very minor inconvenience. It is pretty canned.
If you do use the memories, you are in effect treating the rig as a giant HT, which throws away a lot of functionality.
73s,
Alan WA4SCA