Well you have been busy with the mods!! :D
Have a look at
this site for Disco tyre fitting options.
Larger tyres do bring one small problem if you go too large (i.e 33" Dia like I have) in that it changes the gearing of the vehicle and it starts to stuggle to get up hills in 5th, 30mph can only be done in 3rd and your speedo reads upto 6mph slow.
You can correct this but it means changing the transfer box to a 1.4 TD5 Defender box (lots of dosh) or changing both front & rear axle diffs to 4.11 ratio (even more dosh!!). The former will only alter the Hi-ratio gearing so your low box will remain slightly over geared where as the latter will do both hi & low. ;)
If your looking at other mods then you may notice with the 2" lift that the vehicle's steering in lighter than before and will tend to "tramline" or follow the lines in the tarmac. This due to the change in the caster angle on the front steering due to the lift.
You can correct this with caster correction radus arms from QT Services or Scorpion Racing.
If your fitting larger Dia tyres then you may want to look at extended chassis bump stops. These stop the tyres hitting the inner wheelarch on full articulation.
http://www.paddock-spares.com do these at a reasonable price.
They also do other off-road gear like spring retainers and dislocation cones on there!!
Upto 32" Dia tyres will go on the rear wheel carrier without a problem, any larger than that and it will hit the rear bumper when you shut the rear door.
Devon 4x4 do a nice wheel carrier that will take upto 35" tyres on the back door and if your looking to go that large then you may want to look at the wheel arch flares they do as well. Not cheap (over £200 for a set) but they look the mutts whats'its!! :D
There, that should keep you thinking for a while anyway!!
And here's what I've done to mine....................