There aren't many options as there's no such thing as "chrome" paint, only silver (don't be fooled by the spray cans sold at places like Supercrap/Ricerbarn with lovely and shiny chrome caps - it's deceptive as they're silver not chrome!). The only way to chrome something is by electroplating, but it is expensive.
If cost isn't an issue and you want the best, i'd suggest you buy a brand new set of grilles from Holden. Then send them to somewhere like "The Bronzing Studio/Chrometech" in Sydney (Castle Hill). In 2007 i had a pair of VT grilles done (after spending a lot of time and effort removing the vertical slats) - back then the chroming cost $160 each (see pics #1 & #2). It was a professional job and looked tops, but only lasted six months. I do a lot of k's particularly highway driving. I found they chipped easily and and both started peeling very slightly at the top corners. It's up to you, if you just want them for show (car shows, photography, etc) then go for it, but if it's an everyday driver i don't think i'd bother.
Stone chips and chromed plastic don't go well together (check any VX Berlina/Calais grille and you'll see what i mean). The old cars pre-70's got away with it because all the chrome bits were actual metal underneath (and therefore more resistant to stone chips, cracking/peeling, etc). My honest advice to you is get a new set and paint them (2-pac at a panel shop, not by using an acryllic spray can etc). Perhaps body colour or even gloss black. I ended up buying another set of new black plastic (Executive) grilles, removed the grilles (again!) and prepared them, then had them painted body colour at a panel shop (see pic #3). Obviously removing the cross-hatched slats in your VXII Acclaim grille would be much more difficult then vertical-only slats in VT ones, but if you paint them as they are, they should look ok.
Just my 2¢ anyway...