be sure to check the frame area on the passenger side, behind the cab. they're notorious for rusting through there first. also, check the brake hard lines on the passenger frame rail, between the frame and gas tank. if used in mud, it will pack there and rust the line to the point that it'll rupture.
Toyota's ifs is one of the best available, as long as the tire size is kept moderate (around 35-36 max). above that and ball joints and half-shafts suffer.
The same can also be said for the solid axle. the newer, the better, as toyota added gussets to the front housing in the later years.
I personally haven't found any flaws in the use of the stock carb on a toyota. if adjusted properly, it handles hills and angles as good as FI.