To be honest your bleach highlights will be porous so whatever you choose will fade quickly so I wouldn't go too light. 7.3 or 73 mixed with 7.0/7 or dark golden blonde mixed with dark blonde will be nice. You can mix half of each then use it again when it fades.
My hair sounds like the same colour as yours. I had it highlighted for years but stopped when preg with DD. after she was born i had balayage to blend the two contrasts better and then let nature take it's course. It looked really cool actually... Sun kissed. All the blond has mostly gone now just a few natural streaks and i love it's condition... I used to hate the colour but now i love it- it's different and looks healthy too. Go for it!!