Hello chap, welcome to UK-P
A debadged grille, brand new, is about £120 at the moment for a kamei item. To get one cheaper you'd probably have to source one off eBay or a second-hand sale on the forum? Foglights will look pretty sweet, even if you don't get around to wiring them up just having them in the bumper it'll make a positive impact on the looks
GTi-spec gas discharge headlights will look superb but might be a pain, there's a lot to think about, the lights, the ballasts, the headlight washers, the whole setting up of them... bit of a 'mare! JWC on here has done it to his car, might be worth asking him what is needed for the job?
Nice Polo btw, a good bit of colour-coding going on there, and something a bit different to what we usually see! Where'd you get your sunstrip done mate - done with the tints I guess?
Cheers