Ivochka,
my recommendation is for you to apply to check if Russia's processing center is faster than Buffalo. Let me know if you need the link.
If you must file through Buffalo, then you will need to do your FBI report befofre you leave. You will also need an address in the US that you will not change on file till this is all sorted out because once you change your address on file after you move to russia, they will transfer your file to russia and that will add more months/year to the timeline. So find an address in the US if you must use Buffalo office.
And do your FBI before leaving. If they call you for an interview, you may then fly back for the interview....that will be price of applying through buffalo.
Olusolalekan