1.)what spacers should I buy to improve the stance
I would say 21mm fill the arches nicely.
2.) what induction kit to improve the sound and possibly performance
The KTec kit makes a good noise but I think that there are mixed views on whether it increases performance. If you want induction noise then get the KTec kit.
3.) is a air filter required if so which? - If you go for a KTec induction kit you won't need a filter
4.) I can’t afford an aka exhaust. I want to increase the sound of the exhaust am I best to get a full system if so which? Or should I take the cat out of the current one and get an aka box welded in
Akra's are expensive but make, in my opinion, the perfect noise. A full Akrapovic Evolution system has the mid section through to the back box and gets rid of the main cat and just uses the pre-cat in the OEM manifold. If you buy or can find a used Akra back box you might be able to take out the main cat and still pass an emissions test - but I a not 100% sure on this point.
If I was starting on another Clio I would put on a good set of tyres like some Michelin PS4s, make sure the
brake discs and pads were in good condition. Then ensure the suspension is in good order. From there make sure you have no knackered bushes. Check that your belts have been done within the past 5 years - but it sounds like they have if they were done 10,000 miles ago. From there you should have a good base to work from.
If you don't want to go to the expense of finding some projector headlights just use some Philips Crystal Vision bulbs so that you don't have the yellow hue from the headlights.
I went through a stage of wanting to have gloss black bump strips but now like that my Cup can be identified as a Cup because of the black plastic bump strips.