In Forest of the Dead right before she died, she explains what happened the last time she met him:
RIVER: Funny thing is, this means you've always known how I was going to die. All the time we've been together, you knew I was coming here. The last time I saw you, the real you, the future you, I mean, you turned up on my doorstep, with a new haircut and a suit. You took me to Darillium to see the Singing Towers. What a night that was. The Towers sang, and you cried.
COMPUTER: Autodestuct in one minute.
RIVER: You wouldn't tell me why, but I suppose you knew it was time. My time. Time to come to the library. You even gave me your screwdriver. That should have been a clue.
(The two screwdrivers and her diary are just out of the Doctor's reach.)
RIVER: There's nothing you can do.
DOCTOR: You can let me do this.
RIVER: If you die here, it'll mean I've never met you.
DOCTOR: Time can be rewritten.
RIVER: Not those times. Not one line. Don't you dare. It's okay. It's okay. It's not over for you. You'll see me again. You've got all of that to come. You and me, time and space you watch us run.
Which Doctor is she referring to that has a new haircut and suit? And which Doctor does she mean when she said "you'll see me again, you've got all of that to come"?