I would guess the 30mm too. No loss if you've already done work on the front, best to check before you get started, nothing worse than getting in to a job, even near the beginning and realising you need to go out and get more bits... I usually get as far as the off-license and give it up for another weekend.
For tightening, although I would recommend you get a solid torque wrench and use the correct specs, what I did for the front, was use an 18 inch breaker bar on the 30mm nut, gentlly pulse a little body weight on top of the bar until it would go no further, then after about 50 miles, checked this again in the same way.
I've yet to order my Christmas present for my wife to wrap this year, so I don't have a suitable torque wrench, I just compare it with calculations using my own body-weight.
The year before last I got a fantastic telescopic ratchet, with minute ratchet action and thick, oil resistant rubber handle, last year it was a magnetic dish (handy on a shelf in the kitchen, behind the radio, to hold some small computer screws) and laser level I've never used, so this year I'll be getting the torque wrench!