This is pretty much the same setup that I will be running in a few months.
I recommend going to the WT diffs. You will get much better articulation, and extra width. This will allow you to fit a wheel with less offset, which will be nicer on your bearings.
Your front gaurds will need some fairly heavy cutting to clear 33's.
I am running 2" lift, RUF and no body lift, so to fit 33's
I have to cut a few inches of my gaurds. Its a big job, but well worth it if you ask me. Also remember that your CV's will not liek 33's for too long, so invest in some chromo's from the states.
Sounds like a nice truck, make with the pics
Go with the WT Diffs! Mine is a NT SJ410 now with WT Diffs -25 offset 15x8 rims with 33" Silverstone Extremes I have a 2" BL and 40mm OME Springs I have massaged the firewall a fair bit but when it's flexed up on full lock it still touches so I will be cutting front end off the sill on an angle, as well as moving the front diff forward about 10-20mm and spacing the shock back but trying to keep in mind that the tyre starts to get closer to the Headlight bucket the further you move it forward!