It's pretty capable stock. Here are some additional options.
The s/c kit has been critiqued by many members who have commented that it gives the accelleration the factory forgot.
Tone tried a set of custom made Bob Land headers and noted little, if any improvement, attesting to a good factory design of exhaust.
You might try contacting SWORDY for some custom tie rod sleeves and ends as this is a weak link when offroading isuzu's. He's laid up for the time being, but might make you a set upon his recovery.
Stinkyfab makes some nice, heavy rear lower control arms in 2 different configurations.
There are various stock and member fabbed skid plates available. The main areas of concern are oil pan and transfer case. The space saver spare has been reported to give the TOD system some difficulty, so you may want to use a top rack with a full size spare tire or carry a can or 2 of fix a flat.