Have you done the lift yet?
If so, get the sizes that the tyre com in, half the diameter of the tyre and measure from the centre of the hub to see how much room they leave in the arch.
Remember to account for articulation though.
If you've not done the lift then get that on there first.
Looking at the ads in the mags than they come in 205R16, 235x85R16 and 265x75R16 so you may need a +2" lift to get anything larger than the 205R16's in there!