Hi and sorry to hear about the Merc.
Probably the " best " all round Z would be a 200 GT, out of the options the best would be Xenons, then it's all the usual stuff - parking / sat nav / heated seats / leather etc.
things to look out for on a MK1 with around 50k miles, all these will have had the cam chain done if not by Peugeot, then the owner, this was an early fault with the MK1's some even say early MK2's - very few.
Look for leaks, damaged jacking points - easily done, check warning lights - view history with Datalink port, listen for any strange noises when changing gear and setting off, try setting off in second - give it ample revs - look for clutch slip,
heating cooling system inc A/C, all these things are not confined to the RCZ but general points to note.
Good luck with your hunt and remember that there is quite a choice out there, so don't let your heart rule your head.
Cheers M. :beer: