Just stick with the suspension you have, it'll be fine and if you can stiffen the rear shocks even better. Get yourself a set of front camber bolts and get the car aligned properly. A good start would be max negative camber either side with a smidge of toe out (-0.6mm or -0.06 degs either side) on the front. The rear is non adjustable just make sure its not to far out of OE spec and you'll be right with this set up.
Get a set of spare 15" track wheels and some used decent track tyres from eBay which are ten a penny in 195/50/15, go with the likes of Toyo R888's, Yoko a048R, Avon ZZR, Kumho V70a, Dunlop DZ etc...The other wheels just get a set of decent road tyres that are good in the wet and they will work as road tyres to get you to the track and also will be good for wets when semi-slicks aren't up to the job.
Brakes wise Brembo HC front discs and PBS front and rear pads is a decent low cost option, rear discs just go Pagid or similar OE spec. Just make sure your brake system is running free and not sticking and change the fluid regularly (every 3-4 days will suffice) OE Pagid 5.1 fluid will do the job fine and is less than £20 for 5L.
I have video footage on track using the above set up and parts if you want to see how it comes together.
Go have fun!
