asad bhai i've recently gone through the same thing, choosing suspension and tires....
basically u should look at ur needs from the setups, the springs from ironman, arb, terrafirma etc etc are there to either give u lift, extra load carrying capacity or both. load carrying is really important if ur going to use things like steel bumpers, heavy winches, over loaded roof racks etc. if not, then there is nothing better than stock springs.
shocks on the other hand are a different story, i read what bk said earlier that they are longer than stock, that is true, but not always (depends on individual shocks), longer shocks have the advantage of increased wheel articulation but the downfall (if used with short springs) that if compressed they can bottom out (meaning the wheel is pushing on the shock even though it has no more room to compress) and this can destroy a shock!! but again it depends on how much longer the shock is than stock.
another advantage of the after market shock is the gas charging, it will enable u to use them under load without failure. for example rallying etc (high speeds off road), under such use its only a matter of time when stock will give up, where as good aftermarket ones will last longer...
my advice would be to keep the stock springs (get kabli ones if u feel they're sagging a bit) as u dont want the lift and i dont think carry extra loads. and get a set of bilstein 5100 shocks (they're the best bang for buck and have a really good ride) as im sure u could use them to benefit in high speed off roading.
tires on the other hand stick to the stock size, if anything just get a larger profile like 75 or 80, but keep width to a minimum. a skinny tire is 99% of the time a better tire 
hope i was of any help
