Are you looking at the Y61 (current shape GU) or the new Y62 with the 5.6 V8?
If you are going new then i cant comment on the old one as you junking it. how much tradein are they offering you? you could get a TD42 put in your car for around the same price as fixing that ZD30 which you would never do.
Your current accessories will likely fit on the new one other than any Bar work you have which will be redundant.
The 2013 GU8 is a perla mate, standard rear diff lock and traction control. Its a whole other world by comparison to what you have now.
Head over to the introduction section here and post an intro mate, we like folks to say G'day