Personaly I would sugest a body lift. Leave all the heavy stuff (engine, gearbox, chassis, drive train) where it is, and lift the body onto 2" 'stilts' over the chassis. As well as not moving you centre of gravity up as much (an advantage both on and off road), but also does not involve moving the transmition from the angle some smart little Japaneas guy spent monthes perfecting. You will still give yourself more room in the wheel arch for bigger tyres, alowing you to lift the diffs.
That said, unless you want to go bigger than 31/10.50/15, or you just want 'the look' I wouldn't lift it at all. This size tyre will fit almost as the car is. All I had to do to get them onto mine was wind the tortion bars up slightly, to bring the front level with the back (instead of the normal nose down stance of the Indi), and bend the front mud flaps back a bit, so they didn't fowl on the tyre at lock. I also removed the stearing stops by the way (OK if you don't over do the loud peddel at lock). And the tyres never foweled on the body as long as I had it, on road or off.