It all depends on your taste and how much money you want to throw at it as well as your insurance situation.
I have done practically nothing to mine for the following reasons:
1) Its a mk2b therefore hardly any decent aftermarket parts available for it
2) Its a 1.2 8v therefore hardly worth tuning
3) Its under warrenty therefore any modifications can void it making the warrenty pointless
4) My insurance will now allow me to run somthing a bit quicker.
My plan has been to save what money that I was going to spend on modifying my mk2b and put it towards either a mk1 GT, mk2 HGT or mk2 JTD depending on what takes my fancy come Feb/March 07.
But if you really are intent on modifying it then I would suggest once you have lowered it you see if you can get your hands on the Active Sport bumpers, Abarth skirts and spoiler. Then see if you can get a badgeless grille.
PM Crazydave and ask him for some ideas as his Active Sport looks fu*king cool