I got lucky for tonics, at the end of my normal run I was lacking one and it was one already on the Xbox360 version so I was able to go back and grab it...
I'm finishing to grab the diaries ( I didn't miss the 5 you can't go back to, lucky again) and then I guess I will start my survivor no vita chamber run then ( have to grab weapon specialist and another trophy I missed due to killing a little too early someone in game ;))
Hint : if you go back through the game while wearing the suit you assemble before the last boss ( not saying more don't wanna spoil it) nothing attacks you so it make grabbing those diaries/tonics you missed very easy..)