if you dont mind scratched/bent doors, then you dont need rock sliders. they will still work fine, just look a little tatty, which can be covered with strategic chequer plate.
diff guard on front is a must IMO
same goes for tow rope and decent recovery points
i would highly advise a tank guard, even if you do have a towball
anti rollbars do seriously restrict performance off road, and IMO its not too bad without them. you would still dare to do drifts lol. maybe, make sure that the bolts to the axles are not seized then it would take 5 minutes to unbolt them and strap them up to the chassis when needed.
a lift isnt necessary, however my views have changed recently and now have decided i would quite like one (wouldnt need if i had a 90)
you dont need heavy duty bumpers, but if they do get so bent that you cant open the rear door you could always botch one up like i did.
apart from diff guards, bash plate, rock sliders, bumper trim, fuel pump fiddle and tyres mines standard and it is ideal for what i need (bearing in mind im only 16 and dont take it on the road)
my landy
mikey
ooh and i have 110 shocks on the rear, which give about 1 inch extra travel (highly unneccesary, but they were cheaper than disco ones)