So the 96 and up HP30's have the larger shafts and knuckles. Correct me if I am wrong but what I have gathered is all HP30 axleshafts will have the 30 spline inners with 27 spline outers? So to do the swap ill need the axleshafts, u-joints, ands spindles from a WJ front HP30?

No, the knuckles for 91+ are all the same.

All d30's have 27 spline inners and outers. Aftermarket Alloy Shafts are available in 30 spline, but as I stated previously you'll need a 30 spline locker or carrier to use those shafts.

No you don't need anything from a WJ to run the shafts that usee the larger 297/760 u-joints. They are a direct swap.

Do they use a C-clip to hold them in place?

The axles are held to the unit bearing bub via the 36mm hub nut.

OEM axles use c-clips to retain the u-joints. Alloy inner/outer combo's generally use full circle clips.