If the chassis has the bolt in cross brace just behind the engine then you want one with the gusset stiffening plates a few inches behind it where the top tubes meet the main cross tube. If the chassis has the welded in triangulated stiffeners instead of the bolt in cross brace that is better.
The "comfort kit" steering modification is essential.
If you drive in traffic a lot or in hot climates then the cooling kit would be a good idea.
The noise reduction kit for the bevel box is of debatable worth...
Some may disagree with me!
Well, I agree with all of that, Calum, but I would add:
Make sure that you have the Centa rather than one of the earlier compensators.
