You can fit decent speakers. And it you wanted extra and to overpower the general road/wind noise of a defender you can put them in the headlining right next to you ear. That is where I have mine.
Cruise control come into the same catagory of Modern superfluousness as parking sensor in my opinion. Although I know if you are that way inclined you can fit it to the electronically controlled variants you are looking at so you could retro fit if it doesn’t come with it.
In terms of AC the TD5 comes with the original AC they got rid of on the tdci. You move your left hand forward a little and there is a magic lever that opens the cabin to a whole new world of refreshing air flow.
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On a more serious not I have done Morocco twice and driven through the Sahara with nothing more than the front vents fitted to my 110. As long as you are moving above about 10mph they are more than sufficient to cool the cabin. And combined with adopting the correct driving position of elbow out an open window regardless of weather I have never missed not having AC.