jonnyjogpants said:
how much should i spend and what should i get
Personally I'd get FK coilovers (~£550 from john2modified etc) then get them set up and the car corner weighed (£120 or so) fit them yourself for free or get the garage doing the corner weight to do ti for £90.
Thats will make the biggest difference to the car I'd personally go down this route before any idea of just dampers and spending money on brakes etc as stock ones are fine.
Is you want to spend some more then get some nice light wheels 15's are a good compromise 16's look better and will give a bit more grip as there bigger tyes) so long as you have a good offset then it will be much better on a bumpy back road as the rotating mass is less so it will grip better.
If you want to spend some more then learn to drive on track by this point you'll probably find the stock brakes aren't lasting so upgrade to 4 pots using the same disks (£400) but it will be more through the fact your needing to bleed the brakes and change pads rarther than fade and better to module brakes you'd upgrade.
You shouldn't have any trouble with the brakes fading if you do best idea is to bleed the sytem with better fluid as the brakes are the same as fitted to the Williams which had 150 hp so a 1.2 with 75hp isn't exactly pushed to its limits. You don't need any harder pads though (I've yet to have probablem with the expensive £17 halford own) but if you do DS2500's are a mid rnage price option but at £80 or so a set there not massively cheap.