If you want an E85 (facelift version post 2006) go for the Sport - 2.0i Sport as it comes with M sport extras (steering wheel, sports leather seats, m sport suspension and wheels). There were some very nicely finished specials in 2008. Go for heated seats (manual are ok but if heated they are generally electric as well). Parking assist is a help when reversing. Cruise is nice as is uprated sound system.
As mrwilks has said the market is flooded with 2 litres so you can hold out for your preferred colour and options if patient .
The 2 litre does have issues though - cracked exhaust manifolds and engine warning lights due to over sensitive sensors (which can be an irritation and hassle). Find a good specialist and they'll be able to weld the exhaust and buy a code reader (cheap on ebay) and turn off the warning lights yourself (when you've had them checked of course!)
35000 miles is low so it will inflate the price but you'll be surprised how little servicing might have been done (should be every 2 years but with that mileage sometimes it can be as little as 2 services due to mileage based servicing). Check tyres (they are as expensive as the 6 cylinder Zeds, same size - a staggered set of mid premium tyres can be had for £90 fronts each and £120 rears. Make certain all the usual maintenance issues are ok as even the 2 litres are effective and capable sports cars so brakes particularly need to be in good condition - fluid changed every 2 years (cheap at my independent specialist (£20 + £6 fluid) and so on - there is a good introduction to the Zed and what to look out for on this forum - see the introduction (sticky) posts.
Ask if there has been any problem with the roof motor - they are about £300 for the motor and at least £200 pound extra to be fitted. We all use a guy up here who relocates the motor into the boot for £80 making the issue of roof motors corroding due to water, redundant.
Maintaining the Zed can be surprisingly affordable with the right Zed, the right contacts and through the forum. Get your son to read through the posts on the forum as there's lots of info on here.
I had a 2 litre first and loved it but do look into the 6 cylinder versions as they can be nearly as cheap to run, are more desirable and more easily sold on - especially true of the 3 litre. As already mentioned the 2.2 and 2.5 can be found cheaper.
Good luck with your search - when your sorted get your son to join the forum
How much are they asking for the 2008 2 litre? Even at 35000 miles I would want to be around 6K or less.
that's at least 2.5Si money if not 3.0Si & I know where id want my £ :wink: